Tag Archives: AWS Organizations

Building AWS Lambda governance and guardrails

Post Syndicated from Julian Wood original https://aws.amazon.com/blogs/compute/building-aws-lambda-governance-and-guardrails/

When building serverless applications using AWS Lambda, there are a number of considerations regarding security, governance, and compliance. This post highlights how Lambda, as a serverless service, simplifies cloud security and compliance so you can concentrate on your business logic. It covers controls that you can implement for your Lambda workloads to ensure that your applications conform to your organizational requirements.

The Shared Responsibility Model

The AWS Shared Responsibility Model distinguishes between what AWS is responsible for and what customers are responsible for with cloud workloads. AWS is responsible for “Security of the Cloud” where AWS protects the infrastructure that runs all the services offered in the AWS Cloud. Customers are responsible for “Security in the Cloud”, managing and securing their workloads. When building traditional applications, you take on responsibility for many infrastructure services, including operating systems and network configuration.

Traditional application shared responsibility

Traditional application shared responsibility

One major benefit when building serverless applications is shifting more responsibility to AWS so you can concentrate on your business applications. AWS handles managing and patching the underlying servers, operating systems, and networking as part of running the services.

Serverless application shared responsibility

Serverless application shared responsibility

For Lambda, AWS manages the application platform where your code runs, which includes patching and updating the managed language runtimes. This reduces the attack surface while making cloud security simpler. You are responsible for the security of your code and AWS Identity and Access Management (IAM) to the Lambda service and within your function.

Lambda is SOCHIPAAPCI, and ISO-compliant. For more information, see Compliance validation for AWS Lambda and the latest Lambda certification and compliance readiness services in scope.

Lambda isolation

Lambda functions run in separate isolated AWS accounts that are dedicated to the Lambda service. Lambda invokes your code in a secure and isolated runtime environment within the Lambda service account. A runtime environment is a collection of resources running in a dedicated hardware-virtualized Micro Virtual Machines (MVM) on a Lambda worker node.

Lambda workers are bare metalEC2 Nitro instances, which are managed and patched by the Lambda service team. They have a maximum lease lifetime of 14 hours to keep the underlying infrastructure secure and fresh. MVMs are created by Firecracker, an open source virtual machine monitor (VMM) that uses Linux’s Kernel-based Virtual Machine (KVM) to create and manage MVMs securely at scale.

MVMs maintain a strong separation between runtime environments at the virtual machine hardware level, which increases security. Runtime environments are never reused across functions, function versions, or AWS accounts.

Isolation model for AWS Lambda workers

Isolation model for AWS Lambda workers

Network security

Lambda functions always run inside secure Amazon Virtual Private Cloud (Amazon VPCs) owned by the Lambda service. This gives the Lambda function access to AWS services and the public internet. There is no direct network inbound access to Lambda workers, runtime environments, or Lambda functions. All inbound access to a Lambda function only comes via the Lambda Invoke API, which sends the event object to the function handler.

You can configure a Lambda function to connect to private subnets in a VPC in your account if necessary, which you can control with IAM condition keys . The Lambda function still runs inside the Lambda service VPC but sends all network traffic through your VPC. Function outbound traffic comes from your own network address space.

AWS Lambda service VPC with VPC-to-VPC NAT to customer VPC

AWS Lambda service VPC with VPC-to-VPC NAT to customer VPC

To give your VPC-connected function access to the internet, route outbound traffic to a NAT gateway in a public subnet. Connecting a function to a public subnet doesn’t give it internet access or a public IP address, as the function is still running in the Lambda service VPC and then routing network traffic into your VPC.

All internal AWS traffic uses the AWS Global Backbone rather than traversing the internet. You do not need to connect your functions to a VPC to avoid connectivity to AWS services over the internet. VPC connected functions allow you to control and audit outbound network access.

You can use security groups to control outbound traffic for VPC-connected functions and network ACLs to block access to CIDR IP ranges or ports. VPC endpoints allow you to enable private communications with supported AWS services without internet access.

You can use VPC Flow Logs to audit traffic going to and from network interfaces in your VPC.

Runtime environment re-use

Each runtime environment processes a single request at a time. After Lambda finishes processing the request, the runtime environment is ready to process an additional request for the same function version. For more information on how Lambda manages runtime environments, see Understanding AWS Lambda scaling and throughput.

Data can persist in the local temporary filesystem path, in globally scoped variables, and in environment variables across subsequent invocations of the same function version. Ensure that you only handle sensitive information within individual invocations of the function by processing it in the function handler, or using local variables. Do not re-use files in the local temporary filesystem to process unencrypted sensitive data. Do not put sensitive or confidential information into Lambda environment variables, tags, or other freeform fields such as Name fields.

For more Lambda security information, see the Lambda security whitepaper.

Multiple accounts

AWS recommends using multiple accounts to isolate your resources because they provide natural boundaries for security, access, and billing. Use AWS Organizations to manage and govern individual member accounts centrally. You can use AWS Control Tower to automate many of the account build steps and apply managed guardrails to govern your environment. These include preventative guardrails to limit actions and detective guardrails to detect and alert on non-compliance resources for remediation.

Lambda access controls

Lambda permissions define what a Lambda function can do, and who or what can invoke the function. Consider the following areas when applying access controls to your Lambda functions to ensure least privilege:

Execution role

Lambda functions have permission to access other AWS resources using execution roles. This is an AWS principal that the Lambda service assumes which grants permissions using identity policy statements assigned to the role. The Lambda service uses this role to fetch and cache temporary security credentials, which are then available as environment variables during a function’s invocation. It may re-use them across different runtime environments that use the same execution role.

Ensure that each function has its own unique role with the minimum set of permissions..

Identity/user policies

IAM identity policies are attached to IAM users, groups, or roles. These policies allow users or callers to perform operations on Lambda functions. You can restrict who can create functions, or control what functions particular users can manage.

Resource policies

Resource policies define what identities have fine-grained inbound access to managed services. For example, you can restrict which Lambda function versions can add events to a specific Amazon EventBridge event bus. You can use resource-based policies on Lambda resources to control what AWS IAM identities and event sources can invoke a specific version or alias of your function. You also use a resource-based policy to allow an AWS service to invoke your function on your behalf. To see which services support resource-based policies, see “AWS services that work with IAM”.

Attribute-based access control (ABAC)

With attribute-based access control (ABAC), you can use tags to control access to your Lambda functions. With ABAC, you can scale an access control strategy by setting granular permissions with tags without requiring permissions updates for every new user or resource as your organization scales. You can also use tag policies with AWS Organizations to standardize tags across resources.

Permissions boundaries

Permissions boundaries are a way to delegate permission management safely. The boundary places a limit on the maximum permissions that a policy can grant. For example, you can use boundary permissions to limit the scope of the execution role to allow only read access to databases. A builder with permission to manage a function or with write access to the applications code repository cannot escalate the permissions beyond the boundary to allow write access.

Service control policies

When using AWS Organizations, you can use Service control policies (SCPs) to manage permissions in your organization. These provide guardrails for what actions IAM users and roles within the organization root or OUs can do. For more information, see the AWS Organizations documentation, which includes example service control policies.

Code signing

As you are responsible for the code that runs in your Lambda functions, you can ensure that only trusted code runs by using code signing with the AWS Signer service. AWS Signer digitally signs your code packages and Lambda validates the code package before accepting the deployment, which can be part of your automated software deployment process.

Auditing Lambda configuration, permissions and access

You should audit access and permissions regularly to ensure that your workloads are secure. Use the IAM console to view when an IAM role was last used.

IAM last used

IAM last used

IAM access advisor

Use IAM access advisor on the Access Advisor tab in the IAM console to review when was the last time an AWS service was used from a specific IAM user or role. You can use this to remove IAM policies and access from your IAM roles.

IAM access advisor

IAM access advisor

AWS CloudTrail

AWS CloudTrail helps you monitor, log, and retain account activity to provide a complete event history of actions across your AWS infrastructure. You can monitor Lambda API actions to ensure that only appropriate actions are made against your Lambda functions. These include CreateFunction, DeleteFunction, CreateEventSourceMapping, AddPermission, UpdateEventSourceMapping,  UpdateFunctionConfiguration, and UpdateFunctionCode.

AWS CloudTrail

AWS CloudTrail

IAM Access Analyzer

You can validate policies using IAM Access Analyzer, which provides over 100 policy checks with security warnings for overly permissive policies. To learn more about policy checks provided by IAM Access Analyzer, see “IAM Access Analyzer policy validation”.

You can also generate IAM policies based on access activity from CloudTrail logs, which contain the permissions that the role used in your specified date range.

IAM Access Analyzer

IAM Access Analyzer

AWS Config

AWS Config provides you with a record of the configuration history of your AWS resources. AWS Config monitors the resource configuration and includes rules to alert when they fall into a non-compliant state.

For Lambda, you can track and alert on changes to your function configuration, along with the IAM execution role. This allows you to gather Lambda function lifecycle data for potential audit and compliance requirements. For more information, see the Lambda Operators Guide.

AWS Config includes Lambda managed config rules such as lambda-concurrency-check, lambda-dlq-check, lambda-function-public-access-prohibited, lambda-function-settings-check, and lambda-inside-vpc. You can also write your own rules.

There are a number of other AWS services to help with security compliance.

  1. AWS Audit Manager: Collect evidence to help you audit your use of cloud services.
  2. Amazon GuardDuty: Detect unexpected and potentially unauthorized activity in your AWS environment.
  3. Amazon Macie: Evaluates your content to identify business-critical or potentially confidential data.
  4. AWS Trusted Advisor: Identify opportunities to improve stability, save money, or help close security gaps.
  5. AWS Security Hub: Provides security checks and recommendations across your organization.


Lambda makes cloud security simpler by taking on more responsibility using the AWS Shared Responsibility Model. Lambda implements strict workload security at scale to isolate your code and prevent network intrusion to your functions. This post provides guidance on assessing and implementing best practices and tools for Lambda to improve your security, governance, and compliance controls. These include permissions, access controls, multiple accounts, and code security. Learn how to audit your function permissions, configuration, and access to ensure that your applications conform to your organizational requirements.

For more serverless learning resources, visit Serverless Land.

How to track AWS account metadata within your AWS Organizations

Post Syndicated from Jonathan Nguyen original https://aws.amazon.com/blogs/architecture/how-to-track-aws-account-metadata-within-your-aws-organizations/

United States Automobile Association (USAA) is a San Antonio-based insurance, financial services, banking, and FinTech company supporting millions of military members and their families. USAA has partnered with Amazon Web Services (AWS) to digitally transform and build multiple USAA solutions that help keep members safe and save members’ money and time.

Why build an AWS account metadata solution?

The USAA Cloud Program developed a centralized solution for collecting all AWS account metadata to facilitate core enterprise functions, such as financial management, remediation of vulnerable and insecure configurations, and change release processes for critical application and infrastructure changes.

Companies without centralized metadata solutions may have distributed documents and wikis that contain account metadata, which has to be updated manually. Manually inputting/updating information generally leads to outdated or incorrect metadata and, in addition, requires individuals to reach out to multiple resources and teams to collect specific information.

Solution overview

USAA utilizes AWS Organizations and a series of GitLab projects to create, manage, and baseline all AWS accounts and infrastructure within the organization, including identity and access management, security, and networking components. Within their GitLab projects, each deployment uses a GitLab baseline version that determines what version of the project was provisioned within the AWS account.

During the creation and onboarding of new AWS accounts, which are created for each application team and use-case, there is specific data that is used for tracking and governance purposes, and applied across the enterprise. USAA’s Public Cloud Security team took an opportunity within a hackathon event to develop the solution depicted in Figure 1.

  1. AWS account is created conforming to a naming convention and added to AWS Organizations.

Metadata tracked per AWS account includes:

    • AWS account name
    • Points of contact
    • Line of business (LOB)
    • Cost center #
    • Application ID #
    • Status
    • Cloud governance record #
    • GitLab baseline version
  1. Amazon EventBridge rule invokes AWS Step Functions when new AWS accounts are created.
  2. Step Functions invoke an AWS Lambda function to pull AWS account metadata and load into a centralized Amazon DynamoDB table with Streams enabled to support automation.
  3. A private Amazon API Gateway is exposed to USAA’s internal network, which queries the DynamoDB table and provides AWS account metadata.
Overview of USAA architecture automation workflow to manage AWS account metadata

Figure 1. Overview of USAA architecture automation workflow to manage AWS account metadata

After the solution was deployed, USAA teams leveraged the data in multiple ways:

  1. User interface: a front-end user-interface querying the API Gateway to allow internal users on the USAA network to filter and view metadata for any AWS accounts within AWS Organizations.
  2. Event-driven automation: DynamoDB streams for any changes in the table that would invoke a Lambda function, which would check the most recent version from GitLab and the GitLab baseline version in the AWS account. For any outdated deployments, the Lambda function invokes the CI/CD pipeline for that AWS account to deploy a standardized set of IAM, infrastructure, and security resources and configurations.
  3. Incident response: the Cyber Threat Response team reduces mean-time-to-respond by developing automation to query the API Gateway to append points-of-contact, environment, and AWS account name for custom detections as well as Security Hub and Amazon GuardDuty findings.
  4. Financial management: Internal teams have integrated workflows to their applications to query the API Gateway to return cost center, LOB, and application ID to assist with financial reporting and tracking purposes. This replaces manually reviewing the AWS account metadata from an internal and manually updated wiki page.
  5. Compliance and vulnerability management: automated notification systems were developed to send consolidated reports to points-of-contact listed in the AWS account from the API Gateway to remediate non-compliant resources and configurations.


In this post, we reviewed how USAA enabled core enterprise functions and teams to collect, store, and distribute AWS account metadata by developing a secure and highly scalable serverless application natively in AWS. The solution has been leveraged for multiple use-cases, including internal application teams in USAA’s production AWS environment.

Implementing the AWS Well-Architected Custom Lens lifecycle in your organization

Post Syndicated from Robert Hoffman original https://aws.amazon.com/blogs/architecture/implementing-the-aws-well-architected-custom-lens-lifecycle-in-your-organization/

In this blog post, we present a lifecycle that helps you build, validate, and improve your own AWS Well-Architected Custom Lens, in order to roll it out across your whole organization. The AWS Well-Architected Custom Lens is a new feature of the AWS Well-Architected Tool that lets you bring your own best practices to complement the existing Well-Architected Framework.

The Custom Lens lifecycle: how a Custom Lens can benefit your organization

The AWS Well-Architected Custom Lens Lifecycle

Figure 1. The AWS Well-Architected Custom Lens lifecycle

Each organization has its own requirements, processes, best practices, and tools, but the information can be spread over many systems and knowledge bases. A Custom Lens can capture the specifics of a working environment and let coworkers access this information in a single place—from the AWS console—without the need to go to a separate tool. A Custom Lens can be created in a central management account and securely shared with other accounts.

A Custom Lens can be updated periodically as either a major or minor version. If it is a minor version, the change is automatically applied to all accounts that the lens has been shared with. If it is a major version, the user has to accept the updated Custom Lens and a summary of the changes is displayed to the user. Accepting the changes then applies the update for existing workload reviews, and prompts the user to review the workload. Thus, updating a Custom Lens is an effective mechanism to continuously inform teams about new best practices.

In addition, maintaining and improving a Custom Lens continuously helps to identify gaps in organization-wide tooling, guidance, or documentation. You can aggregate feedback and metrics from reviews that have been performed and use it to drive the improvement process of the content. More importantly, the gathered metrics help measure the overall adherence to best practices and requirements in your organization. If you focus on creating clear, concise, and actionable content for your Custom Lens, the time needed to identify and implement improvements is reduced. As teams realize the value of the Custom Lens, more reviews will be performed, and you will receive more data to construct a comprehensive view.

1. Plan

The Plan phase identifies the benefits that a Custom Lens can provide your organization by identifying current gaps. You also define the scope of your Custom Lens, which is the type of content that supports your desired business outcomes. Depending on the scope, you need to identify the appropriate stakeholders and gain support for the initiative.

2. Implement

In the Implement phase, content is created for the Custom Lens with a working group. While doing this, you can identify missing supplementary artefacts, like documentation or tooling. If that is the case, you can create these artefacts and link to them from the Custom Lens Improvement Plan.

As part of the implementation, the Custom Lens is created by uploading a JSON file in the appropriate format to a central management account, then, sharing the lens with the organization’s AWS accounts. You can share the Custom Lens with IAM Principals, such as users, roles, and AWS accounts. For broader and more efficient sharing, you now have the ability to scale by sharing your Custom Lens with individual organizational units or the entire AWS Organizations. This feature reduces management overhead and removes the need for a custom automation.

3. Measure

The Measure phase aggregates feedback and metrics from reviews that have been performed with your Custom Lens; this information is used to drive the improvement process.

The Well-Architected Tool offers a way to share workload reviews, and you can use this to share all reviews with a central AWS account. You can then analyze the reviews in the central account by extracting the data and analyzing it, for example, by building a dashboard. The Well-Architected Lab for building custom reports provides a solution that can be implemented.

4. Improve

In the Improve phase, the gathered metrics and feedback are used to identify areas for future improvement. For example, you might find common gaps among the performed workload reviews, where the same best practices are not fulfilled. When you investigate the root cause, you can learn that the existing content lacks clarity or that the suggested tools are difficult to use.

In addition, improvements, such as content gaps that were not addressed during the first iteration of the Custom Lens, can be added to the backlog before you repeat the cycle.

To roll out changes of your Custom Lens in an automated and repeatable fashion, you can implement the architecture depicted in Figure 2.

Combining AWS CodeCommit with AWS Lambda to update your Custom Lens whenever a file change is pushed to the code repository

Figure 2. Combining AWS CodeCommit with AWS Lambda to update your Custom Lens whenever a file change is pushed to the code repository

This architecture enables automated releases of new versions of your Custom Lens whenever you commit an updated JSON file to the code repository. In detail, the steps are:

  1. The JSON file of your Custom Lens is stored in an AWS CodeCommit repository. An author pushes an updated version of the file to the repository.
  2. The CodeCommit repository is configured with a trigger action that invokes an AWS Lambda function on each commit.
  3. The Lambda function downloads the updated file by using the GetFile API of CodeCommit. Then, the Lambda function imports the updated Custom Lens and publishes it as a new version by using ImportLens and CreateLensVersion APIs of the AWS Well-Architected Tool, then shares the Custom Lens using CreateLensShare.
  4. The updated Custom Lens is available in all accounts that the lens has been shared with.
  5. Reviewers can create new workload reviews with the Custom Lens or upgrade to the newest version for existing workload reviews.


In this blog post, we walked you through the Custom Lens lifecycle, a process to create and continuously improve a Custom Lens for your organization. If you have a special software development lifecycle, a customized security and compliance framework, or other highly specific requirements or best practices that you want disseminated and measurable, learn more about how to create a Custom Lens in the Well-Architected Tool.

AWS Well-Architected is a set of guiding design principles developed by AWS to help organizations build secure, high-performing, resilient, and efficient infrastructure for a variety of applications and workloads. Use the AWS Well-Architected Tool to review your workloads periodically to address important design considerations and ensure that they follow the best practices and guidance of the AWS Well-Architected Framework. For follow up questions or comments, join our growing community on AWS re:Post.

Top 2021 AWS service launches security professionals should review – Part 2

Post Syndicated from Marta Taggart original https://aws.amazon.com/blogs/security/top-2021-aws-service-launches-security-professionals-should-review-part-2/

In Part 1 of this two-part series, we shared an overview of some of the most important 2021 Amazon Web Services (AWS) Security service and feature launches. In this follow-up, we’ll dive deep into additional launches that are important for security professionals to be aware of and understand across all AWS services. There have already been plenty in the first half of 2022, so we’ll highlight those soon, as well.

AWS Identity

You can use AWS Identity Services to build Zero Trust architectures, help secure your environments with a robust data perimeter, and work toward the security best practice of granting least privilege. In 2021, AWS expanded the identity source options, AWS Region availability, and support for AWS services. There is also added visibility and power in the permission management system. New features offer new integrations, additional policy checks, and secure resource sharing across AWS accounts.

AWS Single Sign-On

For identity management, AWS Single Sign-On (AWS SSO) is where you create, or connect, your workforce identities in AWS once and manage access centrally across your AWS accounts in AWS Organizations. In 2021, AWS SSO announced new integrations for JumpCloud and CyberArk users. This adds to the list of providers that you can use to connect your users and groups, which also includes Microsoft Active Directory Domain Services, Okta Universal Directory, Azure AD, OneLogin, and Ping Identity.

AWS SSO expanded its availability to new Regions: AWS GovCloud (US), Europe (Paris), and South America (São Paulo) Regions. Another very cool AWS SSO development is its integration with AWS Systems Manager Fleet Manager. This integration enables you to log in interactively to your Windows servers running on Amazon Elastic Compute Cloud (Amazon EC2) while using your existing corporate identities—try it, it’s fantastic!

AWS Identity and Access Management

For access management, there have been a range of feature launches with AWS Identity and Access Management (IAM) that have added up to more power and visibility in the permissions management system. Here are some key examples.

IAM made it simpler to relate a user’s IAM role activity to their corporate identity. By setting the new source identity attribute, which persists through role assumption chains and gets logged in AWS CloudTrail, you can find out who is responsible for actions that IAM roles performed.

IAM added support for policy conditions, to help manage permissions for AWS services that access your resources. This important feature launch of service principal conditions helps you to distinguish between API calls being made on your behalf by a service principal, and those being made by a principal inside your account. You can choose to allow or deny the calls depending on your needs. As a security professional, you might find this especially useful in conjunction with the aws:CalledVia condition key, which allows you to scope permissions down to specify that this account principal can only call this API if they are calling it using a particular AWS service that’s acting on their behalf. For example, your account principal can’t generally access a particular Amazon Simple Storage Service (Amazon S3) bucket, but if they are accessing it by using Amazon Athena, they can do so. These conditions can also be used in service control policies (SCPs) to give account principals broader scope across an account, organizational unit, or organization; they need not be added to individual principal policies or resource policies.

Another very handy new IAM feature launch is additional information about the reason for an access denied error message. With this additional information, you can now see which of the relevant access control policies (for example, IAM, resource, SCP, or VPC endpoint) was the cause of the denial. As of now, this new IAM feature is supported by more than 50% of all AWS services in the AWS SDK and AWS Command Line Interface, and a fast-growing number in the AWS Management Console. We will continue to add support for this capability across services, as well as add more features that are designed to make the journey to least privilege simpler.

IAM Access Analyzer

AWS Identity and Access Management (IAM) Access Analyzer provides actionable recommendations to set secure and functional permissions. Access Analyzer introduced the ability to preview the impact of policy changes before deployment and added over 100 policy checks for correctness. Both of these enhancements are integrated into the console and are also available through APIs. Access Analyzer also provides findings for external access allowed by resource policies for many services, including a previous launch in which IAM Access Analyzer was directly integrated into the Amazon S3 management console.

IAM Access Analyzer also launched the ability to generate fine-grained policies based on analyzing past AWS CloudTrail activity. This feature provides a great new capability for DevOps teams or central security teams to scope down policies to just the permissions needed, making it simpler to implement least privilege permissions. IAM Access Analyzer launched further enhancements to expand policy checks, and the ability to generate a sample least-privilege policy from past activity was expanded beyond the account level to include an analysis of principal behavior within the entire organization by analyzing log activity stored in AWS CloudTrail.

AWS Resource Access Manager

AWS Resource Access Manager (AWS RAM) helps you securely share your resources across unrelated AWS accounts within your organization or organizational units (OUs) in AWS Organizations. Now you can also share your resources with IAM roles and IAM users for supported resource types. This update enables more granular access using managed permissions that you can use to define access to shared resources. In addition to the default managed permission defined for each shareable resource type, you now have more flexibility to choose which permissions to grant to whom for resource types that support additional managed permissions. Additionally, AWS RAM added support for global resource types, enabling you to provision a global resource once, and share that resource across your accounts. A global resource is one that can be used in multiple AWS Regions; the first example of a global resource is found in AWS Cloud WAN, currently in preview as of this publication. AWS RAM helps you more securely share an AWS Cloud WAN core network, which is a managed network containing AWS and on-premises networks. With AWS RAM global resource sharing, you can use the Cloud WAN core network to centrally operate a unified global network across Regions and accounts.

AWS Directory Service

AWS Directory Service for Microsoft Active Directory, also known as AWS Managed Microsoft Active Directory (AD), was updated to automatically provide domain controller and directory utilization metrics in Amazon CloudWatch for new and existing directories. Analyzing these utilization metrics helps you quantify your average and peak load times to identify the need for additional domain controllers. With this, you can define the number of domain controllers to meet your performance, resilience, and cost requirements.

Amazon Cognito

Amazon Cognito identity pools (federated identities) was updated to enable you to use attributes from social and corporate identity providers to make access control decisions and simplify permissions management in AWS resources. In Amazon Cognito, you can choose predefined attribute-tag mappings, or you can create custom mappings using the attributes from social and corporate providers’ access and ID tokens, or SAML assertions. You can then reference the tags in an IAM permissions policy to implement attribute-based access control (ABAC) and manage access to your AWS resources. Amazon Cognito also launched a new console experience for user pools and now supports targeted sign out through refresh token revocation.

Governance, control, and logging services

There were a number of important releases in 2021 in the areas of governance, control, and logging services.

AWS Organizations

AWS Organizations added a number of important import features and integrations during 2021. Security-relevant services like Amazon Detective, Amazon Inspector, and Amazon Virtual Private Cloud (Amazon VPC) IP Address Manager (IPAM), as well as others like Amazon DevOps Guru, launched integrations with Organizations. Others like AWS SSO and AWS License Manager upgraded their Organizations support by adding support for a Delegated Administrator account, reducing the need to use the management account for operational tasks. Amazon EC2 and EC2 Image Builder took advantage of the account grouping capabilities provided by Organizations to allow cross-account sharing of Amazon Machine Images (AMIs) (for more details, see the Amazon EC2 section later in this post). Organizations also got an updated console, increased quotas for tag policies, and provided support for the launch of an API that allows for programmatic creation and maintenance of AWS account alternate contacts, including the very important security contact (although that feature doesn’t require Organizations). For more information on the value of using the security contact for your accounts, see the blog post Update the alternate security contact across your AWS accounts for timely security notifications.

AWS Control Tower

2021 was also a good year for AWS Control Tower, beginning with an important launch of the ability to take over governance of existing OUs and accounts, as well as bulk update of new settings and guardrails with a single button click or API call. Toward the end of 2021, AWS Control Tower added another valuable enhancement that allows it to work with a broader set of customers and use cases, namely support for nested OUs within an organization.

AWS CloudFormation Guard 2.0

Another important milestone in 2021 for creating and maintaining a well-governed cloud environment was the re-launch of CloudFormation Guard as Cfn-Guard 2.0. This launch was a major overhaul of the Cfn-Guard domain-specific language (DSL), a DSL designed to provide the ability to test infrastructure-as-code (IaC) templates such as CloudFormation and Terraform to make sure that they conform with a set of constraints written in the DSL by a central team, such as a security organization or network management team.

This approach provides a powerful new middle ground between the older security models of prevention (which provide developers only an access denied message, and often can’t distinguish between an acceptable and an unacceptable use of the same API) and a detect and react model (when undesired states have already gone live). The Cfn-Guard 2.0 model gives builders the freedom to build with IaC, while allowing central teams to have the ability to reject infrastructure configurations or changes that don’t conform to central policies—and to do so with completely custom error messages that invite dialog between the builder team and the central team, in case the rule is unnuanced and needs to be refined, or if a specific exception needs to be created.

For example, a builder team might be allowed to provision and attach an internet gateway to a VPC, but the team can do this only if the routes to the internet gateway are limited to a certain pre-defined set of CIDR ranges, such as the public addresses of the organization’s branch offices. It’s not possible to write an IAM policy that takes into account the CIDR values of a VPC route table update, but you can write a Cfn-Guard 2.0 rule that allows the creation and use of an internet gateway, but only with a defined and limited set of IP addresses.

AWS Systems Manager Incident Manager

An important launch that security professionals should know about is AWS Systems Manager Incident Manager. Incident Manager provides a number of powerful capabilities for managing incidents of any kind, including operational and availability issues but also security issues. With Incident Manager, you can automatically take action when a critical issue is detected by an Amazon CloudWatch alarm or Amazon EventBridge event. Incident Manager runs pre-configured response plans to engage responders by using SMS and phone calls, can enable chat commands and notifications using AWS Chatbot, and runs automation workflows with AWS Systems Manager Automation runbooks. The Incident Manager console integrates with AWS Systems Manager OpsCenter to help you track incidents and post-incident action items from a central place that also synchronizes with third-party management tools such as Jira Service Desk and ServiceNow. Incident Manager enables cross-account sharing of incidents using AWS RAM, and provides cross-Region replication of incidents to achieve higher availability.

AWS CloudTrail

AWS CloudTrail added some great new logging capabilities in 2021, including logging data-plane events for Amazon DynamoDB and Amazon Elastic Block Store (Amazon EBS) direct APIs (direct APIs allow access to EBS snapshot content through a REST API). CloudTrail also got further enhancements to its machine-learning based CloudTrail Insights feature, including a new one called ErrorRate Insights.

Amazon S3

Amazon Simple Storage Service (Amazon S3) is one of the most important services at AWS, and its steady addition of security-related enhancements is always big news. Here are the 2021 highlights.

Access Points aliases

Amazon S3 introduced a new feature, Amazon S3 Access Points aliases. With Amazon S3 Access Points aliases, you can make the access points backwards-compatible with a large amount of existing code that is programmed to interact with S3 buckets rather than access points.

To understand the importance of this launch, we have to go back to 2019 to the launch of Amazon S3 Access Points. Access points are a powerful mechanism for managing S3 bucket access. They provide a great simplification for managing and controlling access to shared datasets in S3 buckets. You can create up to 1,000 access points per Region within each of your AWS accounts. Although bucket access policies remain fully enforced, you can delegate access control from the bucket to its access points, allowing for distributed and granular control. Each access point enforces a customizable policy that can be managed by a particular workgroup, while also avoiding the problem of bucket policies needing to grow beyond their maximum size. Finally, you can also bind an access point to a particular VPC for its lifetime, to prevent access directly from the internet.

With the 2021 launch of Access Points aliases, Amazon S3 now generates a unique DNS name, or alias, for each access point. The Access Points aliases look and acts just like an S3 bucket to existing code. This means that you don’t need to make changes to older code to use Amazon S3 Access Points; just substitute an Access Points aliases wherever you previously used a bucket name. As a security team, it’s important to know that this flexible and powerful administrative feature is backwards-compatible and can be treated as a drop-in replacement in your various code bases that use Amazon S3 but haven’t been updated to use access point APIs. In addition, using Access Points aliases adds a number of powerful security-related controls, such as permanent binding of S3 access to a particular VPC.

Bucket Keys

Amazon S3 launched support for S3 Inventory and S3 Batch Operations to identify and copy objects to use S3 Bucket Keys, which can help reduce the costs of server-side encryption (SSE) with AWS Key Management Service (AWS KMS).

S3 Bucket Keys were launched at the end of 2020, another great launch that security professionals should know about, so here is an overview in case you missed it. S3 Bucket Keys are data keys generated by AWS KMS to provide another layer of envelope encryption in which the outer layer (the S3 Bucket Key) is cached by S3 for a short period of time. This extra key layer increases performance and reduces the cost of requests to AWS KMS. It achieves this by decreasing the request traffic from Amazon S3 to AWS KMS from a one-to-one model—one request to AWS KMS for each object written to or read from Amazon S3—to a one-to-many model using the cached S3 Bucket Key. The S3 Bucket Key is never stored persistently in an unencrypted state outside AWS KMS, and so Amazon S3 ultimately must always return to AWS KMS to encrypt and decrypt the S3 Bucket Key, and thus, the data. As a result, you still retain control of the key hierarchy and resulting encrypted data through AWS KMS, and are still able to audit Amazon S3 returning periodically to AWS KMS to refresh the S3 Bucket Keys, as logged in CloudTrail.

Returning to our review of 2021, S3 Bucket Keys gained the ability to use Amazon S3 Inventory and Amazon S3 Batch Operations automatically to migrate objects from the higher cost, slightly lower-performance SSE-KMS model to the lower-cost, higher-performance S3 Bucket Keys model.

Simplified ownership and access management

The final item from 2021 for Amazon S3 is probably the most important of all. Last year was the year that Amazon S3 achieved fully modernized object ownership and access management capabilities. You can now disable access control lists to simplify ownership and access management for data in Amazon S3.

To understand this launch, we need to go in time to the origins of Amazon S3, which is one of the oldest services in AWS, created even before IAM was launched in 2011. In those pre-IAM days, a storage system like Amazon S3 needed to have some kind of access control model, so Amazon S3 invented its own: Amazon S3 access control lists (ACLs). Using ACLs, you could add access permissions down to the object level, but only with regard to access by other AWS account principals (the only kind of identity that was available at the time), or public access (read-only or read-write) to an object. And in this model, objects were always owned by the creator of the object, not the bucket owner.

After IAM was introduced, Amazon S3 added the bucket policy feature, a type of resource policy that provides the rich features of IAM, including full support for all IAM principals (users and roles), time-of-day conditions, source IP conditions, ability to require encryption, and more. For many years, Amazon S3 access decisions have been made by combining IAM policy permissions and ACL permissions, which has served customers well. But the object-writer-is-owner issue has often caused friction. The good news for security professionals has been that a deny by either type of access control type overrides an allow by the other, so there were no security issues with this bi-modal approach. The challenge was that it could be administratively difficult to manage both resource policies—which exist at the bucket and access point level—and ownership and ACLs—which exist at the object level. Ownership and ACLs might potentially impact the behavior of only a handful of objects, in a bucket full of millions or billions of objects.

With the features released in 2021, Amazon S3 has removed these points of friction, and now provides the features needed to reduce ownership issues and to make IAM-based policies the only access control system for a specified bucket. The first step came in 2020 with the ability to make object ownership track bucket ownership, regardless of writer. But that feature applied only to newly-written objects. The final step is the 2021 launch we’re highlighting here: the ability to disable at the bucket level the evaluation of all existing ACLs—including ownership and permissions—effectively nullifying all object ACLs. From this point forward, you have the mechanisms you need to govern Amazon S3 access with a combination of S3 bucket policies, S3 access point policies, and (within the same account) IAM principal policies, without worrying about legacy models of ACLs and per-object ownership.

Additional database and storage service features

AWS Backup Vault Lock

AWS Backup added an important new additional layer for backup protection with the availability of AWS Backup Vault Lock. A vault lock feature in AWS is the ability to configure a storage policy such that even the most powerful AWS principals (such as an account or Org root principal) can only delete data if the deletion conforms to the preset data retention policy. Even if the credentials of a powerful administrator are compromised, the data stored in the vault remains safe. Vault lock features are extremely valuable in guarding against a wide range of security and resiliency risks (including accidental deletion), notably in an era when ransomware represents a rising threat to data.

Prior to AWS Backup Vault Lock, AWS provided the extremely useful Amazon S3 and Amazon S3 Glacier vault locking features, but these previous vaulting features applied only to the two Amazon S3 storage classes. AWS Backup, on the other hand, supports a wide range of storage types and databases across the AWS portfolio, including Amazon EBS, Amazon Relational Database Service (Amazon RDS) including Amazon Aurora, Amazon DynamoDB, Amazon Neptune, Amazon DocumentDB, Amazon Elastic File System (Amazon EFS), Amazon FSx for Lustre, Amazon FSx for Windows File Server, Amazon EC2, and AWS Storage Gateway. While built on top of Amazon S3, AWS Backup even supports backup of data stored in Amazon S3. Thus, this new AWS Backup Vault Lock feature effectively serves as a vault lock for all the data from most of the critical storage and database technologies made available by AWS.

Finally, as a bonus, AWS Backup added two more features in 2021 that should delight security and compliance professionals: AWS Backup Audit Manager and compliance reporting.

Amazon DynamoDB

Amazon DynamoDB added a long-awaited feature: data-plane operations integration with AWS CloudTrail. DynamoDB has long supported the recording of management operations in CloudTrail—including a long list of operations like CreateTable, UpdateTable, DeleteTable, ListTables, CreateBackup, and many others. What has been added now is the ability to log the potentially far higher volume of data operations such as PutItem, BatchWriteItem, GetItem, BatchGetItem, and DeleteItem. With this launch, full database auditing became possible. In addition, DynamoDB added more granular control of logging through DynamoDB Streams filters. This feature allows users to vary the recording in CloudTrail of both control plane and data plane operations, at the table or stream level.

Amazon EBS snapshots

Let’s turn now to a simple but extremely useful feature launch affecting Amazon Elastic Block Store (Amazon EBS) snapshots. In the past, it was possible to accidently delete an EBS snapshot, which is a problem for security professionals because data availability is a part of the core security triad of confidentiality, integrity, and availability. Now you can manage that risk and recover from accidental deletions of your snapshots by using Recycle Bin. You simply define a retention policy that applies to all deleted snapshots, and then you can define other more granular policies, for example using longer retention periods based on snapshot tag values, such as stage=prod. Along with this launch, the Amazon EBS team announced EBS Snapshots Archive, a major price reduction for long-term storage of snapshots.

AWS Certificate Manager Private Certificate Authority

2021 was a big year for AWS Certificate Manager (ACM) Private Certificate Authority (CA) with the following updates and new features:

Network and application protection

We saw a lot of enhancements in network and application protection in 2021 that will help you to enforce fine-grained security policies at important network control points across your organization. The services and new capabilities offer flexible solutions for inspecting and filtering traffic to help prevent unauthorized resource access.


AWS WAF launched AWS WAF Bot Control, which gives you visibility and control over common and pervasive bots that consume excess resources, skew metrics, cause downtime, or perform other undesired activities. The Bot Control managed rule group helps you monitor, block, or rate-limit pervasive bots, such as scrapers, scanners, and crawlers. You can also allow common bots that you consider acceptable, such as status monitors and search engines. AWS WAF also added support for custom responses, managed rule group versioning, in-line regular expressions, and Captcha. The Captcha feature has been popular with customers, removing another small example of “undifferentiated work” for customers.

AWS Shield Advanced

AWS Shield Advanced now automatically protects web applications by blocking application layer (L7) DDoS events with no manual intervention needed by you or the AWS Shield Response Team (SRT). When you protect your resources with AWS Shield Advanced and enable automatic application layer DDoS mitigation, Shield Advanced identifies patterns associated with L7 DDoS events and isolates this anomalous traffic by automatically creating AWS WAF rules in your web access control lists (ACLs).

Amazon CloudFront

In other edge networking news, Amazon CloudFront added support for response headers policies. This means that you can now add cross-origin resource sharing (CORS), security, and custom headers to HTTP responses returned by your CloudFront distributions. You no longer need to configure your origins or use custom [email protected] or CloudFront Functions to insert these headers.

CloudFront Functions were another great 2021 addition to edge computing, providing a simple, inexpensive, and yet highly secure method for running customer-defined code as part of any CloudFront-managed web request. CloudFront functions allow for the creation of very efficient, fine-grained network access filters, such the ability to block or allow web requests at a region or city level.

Amazon Virtual Private Cloud and Route 53

Amazon Virtual Private Cloud (Amazon VPC) added more-specific routing (routing subnet-to-subnet traffic through a virtual networking device) that allows for packet interception and inspection between subnets in a VPC. This is particularly useful for highly-available, highly-scalable network virtual function services based on Gateway Load Balancer, including both AWS services like AWS Network Firewall, as well as third-party networking services such as the recently announced integration between AWS Firewall Manager and Palo Alto Networks Cloud Next Generation Firewall, powered by Gateway Load Balancer.

Another important set of enhancements to the core VPC experience came in the area of VPC Flow Logs. Amazon VPC launched out-of-the-box integration with Amazon Athena. This means with a few clicks, you can now use Athena to query your VPC flow logs delivered to Amazon S3. Additionally, Amazon VPC launched three associated new log features that make querying more efficient by supporting Apache Parquet, Hive-compatible prefixes, and hourly partitioned files.

Following Route 53 Resolver’s much-anticipated launch of DNS logging in 2020, the big news for 2021 was the launch of its DNS Firewall capability. Route 53 Resolver DNS Firewall lets you create “blocklists” for domains you don’t want your VPC resources to communicate with, or you can take a stricter, “walled-garden” approach by creating “allowlists” that permit outbound DNS queries only to domains that you specify. You can also create alerts for when outbound DNS queries match certain firewall rules, allowing you to test your rules before deploying for production traffic. Route 53 Resolver DNS Firewall launched with two managed domain lists—malware domains and botnet command and control domains—enabling you to get started quickly with managed protections against common threats. It also integrated with Firewall Manager (see the following section) for easier centralized administration.

AWS Network Firewall and Firewall Manager

Speaking of AWS Network Firewall and Firewall Manager, 2021 was a big year for both. Network Firewall added support for AWS Managed Rules, which are groups of rules based on threat intelligence data, to enable you to stay up to date on the latest security threats without writing and maintaining your own rules. AWS Network Firewall features a flexible rules engine enabling you to define firewall rules that give you fine-grained control over network traffic. As of the launch in late 2021, you can enable managed domain list rules to block HTTP and HTTPS traffic to domains identified as low-reputation, or that are known or suspected to be associated with malware or botnets. Prior to that, another important launch was new configuration options for rule ordering and default drop, making it simpler to write and process rules to monitor your VPC traffic. Also in 2021, Network Firewall announced a major regional expansion following its initial launch in 2020, and a range of compliance achievements and eligibility including HIPAA, PCI DSS, SOC, and ISO.

Firewall Manager also had a strong 2021, adding a number of additional features beyond its initial core area of managing network firewalls and VPC security groups that provide centralized, policy-based control over many other important network security capabilities: Amazon Route 53 Resolver DNS Firewall configurations, deployment of the new AWS WAF Bot Control, monitoring of VPC routes for AWS Network Firewall, AWS WAF log filtering, AWS WAF rate-based rules, and centralized logging of AWS Network Firewall logs.

Elastic Load Balancing

Elastic Load Balancing now supports forwarding traffic directly from Network Load Balancer (NLB) to Application Load Balancer (ALB). With this important new integration, you can take advantage of many critical NLB features such as support for AWS PrivateLink and exposing static IP addresses for applications that still require ALB.

In addition, Network Load Balancer now supports version 1.3 of the TLS protocol. This adds to the existing TLS 1.3 support in Amazon CloudFront, launched in 2020. AWS plans to add TLS 1.3 support for additional services.

The AWS Networking team also made Amazon VPC private NAT gateways available in both AWS GovCloud (US) Regions. The expansion into the AWS GovCloud (US) Regions enables US government agencies and contractors to move more sensitive workloads into the cloud by helping them to address certain regulatory and compliance requirements.


Security professionals should also be aware of some interesting enhancements in AWS compute services that can help improve their organization’s experience in building and operating a secure environment.

Amazon Elastic Compute Cloud (Amazon EC2) launched the Global View on the console to provide visibility to all your resources across Regions. Global View helps you monitor resource counts, notice abnormalities sooner, and find stray resources. A few days into 2022, another simple but extremely useful EC2 launch was the new ability to obtain instance tags from the Instance Metadata Service (IMDS). Many customers run code on Amazon EC2 that needs to introspect about the EC2 tags associated with the instance and then change its behavior depending on the content of the tags. Prior to this launch, you had to associate an EC2 role and call the EC2 API to get this information. That required access to API endpoints, either through a NAT gateway or a VPC endpoint for Amazon EC2. Now, that information can be obtained directly from the IMDS, greatly simplifying a common use case.

Amazon EC2 launched sharing of Amazon Machine Images (AMIs) with AWS Organizations and Organizational Units (OUs). Previously, you could share AMIs only with specific AWS account IDs. To share AMIs within AWS Organizations, you had to explicitly manage sharing of AMIs on an account-by-account basis, as they were added to or removed from AWS Organizations. With this new feature, you no longer have to update your AMI permissions because of organizational changes. AMI sharing is automatically synchronized when organizational changes occur. This feature greatly helps both security professionals and governance teams to centrally manage and govern AMIs as you grow and scale your AWS accounts. As previously noted, this feature was also added to EC2 Image Builder. Finally, Amazon Data Lifecycle Manager, the tool that manages all your EBS volumes and AMIs in a policy-driven way, now supports automatic deprecation of AMIs. As a security professional, you will find this helpful as you can set a timeline on your AMIs so that, if the AMIs haven’t been updated for a specified period of time, they will no longer be considered valid or usable by development teams.

Looking ahead

In 2022, AWS continues to deliver experiences that meet administrators where they govern, developers where they code, and applications where they run. We will continue to summarize important launches in future blog posts. If you’re interested in learning more about AWS services, join us for AWS re:Inforce, the AWS conference focused on cloud security, identity, privacy, and compliance. AWS re:Inforce 2022 will take place July 26–27 in Boston, MA. Registration is now open. Register now with discount code SALxUsxEFCw to get $150 off your full conference pass to AWS re:Inforce. For a limited time only and while supplies last. We look forward to seeing you there!

To stay up to date on the latest product and feature launches and security use cases, be sure to read the What’s New with AWS announcements (or subscribe to the RSS feed) and the AWS Security Blog.

If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, contact AWS Support.

Want more AWS Security news? Follow us on Twitter.


Marta Taggart

Marta is a Seattle-native and Senior Product Marketing Manager in AWS Security Product Marketing, where she focuses on data protection services. Outside of work you’ll find her trying to convince Jack, her rescue dog, not to chase squirrels and crows (with limited success).

Mark Ryland

Mark Ryland

Mark is the director of the Office of the CISO for AWS. He has over 30 years of experience in the technology industry and has served in leadership roles in cybersecurity, software engineering, distributed systems, technology standardization and public policy. Previously, he served as the Director of Solution Architecture and Professional Services for the AWS World Public Sector team.

Get more out of service control policies in a multi-account environment

Post Syndicated from Omar Haq original https://aws.amazon.com/blogs/security/get-more-out-of-service-control-policies-in-a-multi-account-environment/

Many of our customers use AWS Organizations to manage multiple Amazon Web Services (AWS) accounts. There are many benefits to using multiple accounts in your organization, such as grouping workloads with a common business purpose, complying with regulatory frameworks, and establishing strong isolation barriers between applications based on ownership. Customers are even using distinct accounts for development, testing, and production. As these accounts proliferate, customers need a way to centrally set guardrails and controls.

In this blog post, we will walk you through different techniques that you can use to get more out of AWS Organizations service control policies (SCPs) in a multi-account environment. We focus on policy evaluation logic and how SCPs fit into it, show an overview of SCP inheritance, and describe methods for writing compact SCPs. We cover the following five techniques:

  1. Consider the number of policies per entity
  2. Use policy inheritance
  3. Segment by workload type
  4. Combine policies together
  5. Compact your policies

AWS Organizations provides a mechanism to set distinct logical boundaries by using organizational units (OUs). This is useful when you have similar workloads across different AWS accounts that require common guardrails. SCPs are a type of organization policy that you can use to manage permissions in your organization. SCPs offer central control over the maximum available permissions for all accounts in your organization. SCPs help you make sure that your accounts stay within your organization’s access control guidelines. A key distinction of SCPs is that they are useful to set broad guardrails across your environment. You can think of guardrails as a way to enforce specific governance policies at varying levels of your environment, which we will discuss in this post.

Policy evaluation logic and how SCPs fit in

Before we dig into the details, let’s first look at how SCPs work from an overall policy perspective, along with the evaluation logic. An explicit Deny statement in any policy trumps an Allow statement. Organization SCPs that apply to any AWS account that is part of an organization in AWS Organizations require an Allow statement before proceeding in the policy evaluation flow.

For an in-depth look at how policies are evaluated, see Policy evaluation logic in the documentation.

Now, let’s walk through five recommended techniques that can help you get more out of SCPs.

1. Consider the number of policies per entity

An organization is a collection of AWS accounts that you manage together. You can use OUs to group accounts within an organization and administer them as a single unit. This greatly simplifies the management of your accounts. It’s possible to create multiple OUs within a single organization, and you can create OUs within other OUs, otherwise known as nested OUs. You have the flexibility to attach multiple policies to the root of the organization, to an OU, or to an account. For example, in an organization that has the root, one OU, and one account, attaching five SCPs to each of them would produce a total of 15 SCPs (five SCPs at the root, five SCPs at the OU, and five SCPs on the one account).

The number of SCPs that you can apply is limited, and being close to or at the quota could restrict your ability to add more policies in the future. The current published quotas are as follows:

  • Maximum number of SCPs attached to the root: 5
  • Maximum number of SCPs attached to each OU: 5
  • OU maximum nesting in a root: 5 levels of OUs under a root
  • Maximum number of SCPs attached to each account: 5

Note: For the latest information on quotas, see Quotas for AWS Organizations.

Consider the following sample organization structure to understand how you can apply multiple SCPs at different levels in an organization.

Figure 1: A sample organization showing the maximum number of SCPs applicable at each level (root, OU, account)

Figure 1: A sample organization showing the maximum number of SCPs applicable at each level (root, OU, account)

2. Use policy inheritance

Policy inheritance refers to the inheritance of policies that are attached to the organization’s root or to an OU. All accounts that are members of the organization root or OU where a policy is attached are affected by that policy, but inheritance works differently for Allow and Deny statements. For a permission to be allowed for a specified account, every SCP from the root through each OU in the direct path to the account, and even attached to the account itself, must allow that permission. In other words, a statement that allows access needs to exist at every level of a hierarchy; it’s not inherited. However, a Deny statement is inherited and evaluated at each level.

At this point, you should start thinking about the policies from a broader controls perspective: Controls that you want to implement on the whole organization should go into your organization’s root-level SCP. Controls should be more granular as you move down the hierarchy in AWS Organizations.

For example, when a Deny policy is attached to the organization’s root, all accounts in the organization are affected by that policy. When you attach a Deny policy to a specific OU, accounts that are directly under that OU or nested OUs under it are affected by that policy. Because you can attach policies to multiple levels in the organization, accounts might have multiple applicable policy documents, as shown in Figure 2.

Figure 2: Sample organization showing applicable policies

Figure 2: Sample organization showing applicable policies

By default, AWS Organizations attaches an AWS managed SCP named FullAWSAccess to every root and OU when it’s created. This policy allows all services and actions.

Note: Adding an SCP with full AWS access doesn’t give all the principals in an account access to everything. SCPs don’t grant permissions; they are used to filter permissions. Principals still need a policy within the account that grants them access.

Additionally, the policies that are applied to an OU only affect the accounts or the child OUs under it and don’t affect other OUs created under the root. For example, a policy applied to the Sandbox OU doesn’t affect the Workloads OU.

The two tables that follow show examples of the policies that result from inheritance. As discussed previously, if an Allow isn’t present at all levels (root, OU, and account) the account won’t have access to any service. Consider the last example in the Sandbox OU table with a “Deny S3 access” SCP at the root, which limits access to Amazon Simple Storage Service (Amazon S3). Although there is “Allow S3 access” applied to the Sandbox OU and “Full AWS access” at the account level, the resultant policy on account A is “No service access” because there is no policy with an effect of “Allow” in the SCP at the root level.

The following table shows the inheritance of policies in the Sandbox OU.

SCP at root SCP at Sandbox OU SCP at account A Resultant policy at account A Resultant policy at accounts B and C
Full AWS access Full AWS access + deny S3 access Full AWS access + deny EC2 access No S3, no EC2 access No S3 access
Full AWS access Allow Amazon Elastic Compute Cloud (Amazon EC2) access Allow EC2 access Allows EC2 access only Allows EC2 access only
Deny S3 access Allow S3 access Full AWS access No service access No service access

The following table shows the inheritance of policies in the Workloads OU.

SCP at root SCP at Workloads OU SCP at Test OU Resultant policy at account D Resultant policies at production OU/accounts E and F
Full AWS access Full AWS access Full AWS access + deny EC2 access No EC2 access Full AWS access
Full AWS access Full AWS access Allow EC2 access Allows EC2 access Full AWS access
Deny S3 access Full AWS access Allow S3 access No service access No service access

Some examples of common root-level policies are as follows:

For sample SCPs, see Example service control policies. For insight into best practices for applying policies at different levels in an organization, see Best practices for SCPs in a multi-account environment.

3. Segment SCPs by workload type

A key feature of AWS Organizations is the ability to create distinct workload boundaries by using organizational units (OUs). You can think of OUs as a logical boundary where you can directly apply SCPs. You can also nest OUs up to five levels deep and apply different policies at each level. By using OUs, you can segment your workload types and create purpose-driven guardrails to match your security and compliance requirements.

To illustrate this, let’s take an example where there are three distinct workload types divided into three separate OUs: Infrastructure, Sandbox, and Workload, as shown in Figure 3. A best practice would be to tailor your SCPs to each specific OU type. Your security organization wouldn’t want to allow private workloads to be reachable from the internet. However, workloads that serve your external customers would require external network connectivity. To support innovation and experimentation, you can establish a Sandbox OU that has fewer policy restrictions but might limit connectivity back to your corporate data center.

For additional information on how to organize your OUs, see Recommended OUs.

Figure 3: Example organization showing different workloads

Figure 3: Example organization showing different workloads

4. Combine policies together

Similar to AWS Identity and Access Management (IAM) policies, you can have multiple statements within a service control policy. You can combine statements in a single policy to avoid hitting the quota limit of five policies per account, OU, or root. An AWS full access policy is attached by default when you enable SCPs on an organization. You can combine the full access policy with additional controls and combine statements, as shown in the following example policy. Each SCP that you apply can have a policy size of 5,120 bytes. When combining statements, make sure that the resultant statement doesn’t alter your original intent. You can combine the Action elements in an SCP if the policy has the same values for Effect, Resource, and Condition.

AWS full access policy (143 bytes)

    "Version": "2012-10-17",
    "Statement": [
            "Effect": "Allow",
            "Action": "*",
            "Resource": "*"

You can combine this full access policy with the following deny policy:

Deny bucket deletion and Security Hub disablement (260 bytes)

    "Version": "2012-10-17",
    "Statement": [
            "Effect": "Deny",
            "Action": "s3:DeleteBucket",
            "Resource": "*"
            "Effect": "Deny",
            "Action": "securityhub:Disable*",
            "Resource": "*"

The resulting combined policy is as follows:

Combined policy (274 bytes)


5. Compact your policies

One difference between IAM policies and SCPs is that whitespace counts against the size quota in SCPs. Compacting related actions in a policy can help you shorten the policy. Following are four methods to compact your policy:

  1. Remove whitespace. If you use the AWS Management Console, whitespace is automatically removed. However, if you don’t want to manually update policies by using the console every time, you can incorporate a script that removes the whitespace. (Method four later in this list provides an example of this type of script.)
  2. Use wildcards and prefixes to combine multiple actions. For example, the following policy denies access to disable configuration in AWS Security Hub.
         "Effect": "Deny",
         "Resource": "*"

    By using wildcards and prefixes, you can rewrite this policy as follows:

        "Effect": "Deny",
        "Action": "Securityhub:Disable*",
        "Resource": "*"

    Important: When you combine actions together as in this example, be aware that there could be a potential impact if new actions are released in the future that start with the Disable keyword, because these actions will be covered by the wildcard and denied.

  3. SCPs can be configured to work as either deny lists or allow lists. For additional details on allow lists and deny lists, see Strategies for using SCPs. We recommend that you use deny lists where possible, because they are more flexible and can help simplify your policies, which will result in less maintenance. To expand on this strategy, deny statements support conditions (as shown in the following example), and for specific resources to be specified. For example, when AWS adds a new service, you don’t have to go back and update your policy if you’ve used a deny statement. To support this, AWS Organizations attaches an AWS managed SCP named FullAWSAccess to every root and OU when it’s created. This policy allows all services and actions. Additionally, deny statements coupled with NotAction statements can help you write shorter policies.

    Consider the following scenario: Your security organization requires that application teams use specific AWS Regions. The recommended approach is to create a deny list that blocks everything except what is in the NotAction block. Following is an example where the SCP denies any operation outside of specified Regions that your organization has authorized for use.

    Note: The list includes AWS global services that cannot be allowlisted based on a Region.

        "Version": "2012-10-17",
        "Statement": [
                "Sid": "DenyAllOutsideEU",
                "Effect": "Deny",
                "NotAction": [
                "Resource": "*",
                "Condition": {
                    "StringNotEquals": {
                        "aws:RequestedRegion": [

  4. Shorten the Sid value in your policy: The Sid (statement ID) is an optional identifier that you provide for the policy statement. Remove it completely from your policy if it serves no purpose for you. We also have customers who find it effective to maintain a list of SID values and details on corresponding policies in an index file locally.

The following sample Python code can compress a provided policy by removing whitespace and Sid values.

You can export the compressed policy in the file named Compressed_Policy.json or show the output on the terminal by removing # from the following code.

import json
def compress_json(policy):
    statement = policy["Statement"]
    if not isinstance(statement, list):
        statement = [statement]
    for s in statement:
        s.pop("Sid", None)
    # json.dumps removes whitespace around separators in a JSON and converts it to a JSON formatted string.
    # To get the most compact representation, specify separators=(item_separator, key_separator)
    policy_without_whitespace = json.dumps(policy, separators=(',', ':'))
    return policy_without_whitespace

if __name__ == '__main__':
  path = input("Enter the path to policy file like: \n  /Users/swara/Desktop/policy.json or ./policy.json  \n >  ")
  with open(path) as f:
    policy = json.load(f)
original_len = len(str(policy))
mini_policy = compress_json(policy)
#To print the output on the screen
compressed_len = len(str(mini_policy))
print("\n \t original length: {} -> compressed length: {} \n".format(original_len, compressed_len))
#To write output to a file named Compressed_Policy.json
with open("Compressed_Policy.json", "w") as Output_file:
     print(mini_policy, file=Output_file)

Example output on screen:


original length: 433 -> compressed length: 364

To download the sample python code and the example policy shown above, download the files compress-policy.py and policy.json.


In this post, we walked you through different techniques that you can use to get more out of service control policies in a multi-account environment. By using these techniques, you can establish a well-considered strategy for how your organization can adopt SCPs in a multi-account environment. You also learned about how SCPs fit into the overall policy landscape for AWS. SCPs are a powerful tool to help customers establish guardrails. As you evaluate your IAM strategy, consider what you’re trying to achieve. If you’re trying to establish broad guardrails for multiple accounts, then we suggest looking at SCPs first.

If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, contact AWS Support.

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Omar Haq

Omar Haq

Omar is a senior solutions architect with AWS. He has an interest in workload migrations and modernizations, DevOps, containers, and infrastructure security. Omar has previous experience in management consulting, where he worked as a technical lead for various cloud migration projects.

Swara Gandhi

Swara Gandhi

Swara is a solutions architect on the AWS Identity Solutions team. She works on building secure and scalable end-to-end identity solutions. She is passionate about everything identity, security, and cloud.

Monitoring and alerting break-glass access in an AWS Organization

Post Syndicated from Haresh Nandwani original https://aws.amazon.com/blogs/architecture/monitoring-and-alerting-break-glass-access-in-an-aws-organization/

Organizations building enterprise-scale systems require the setup of a secure and governed landing zone to deploy and operate their systems. A landing zone is a starting point from which your organization can quickly launch and deploy workloads and applications with confidence in your security and infrastructure environment as described in What is a landing zone?. Nationwide Building Society (Nationwide) is the world’s largest building society. It is owned by its 16 million members and exists to serve their needs. The Society is one of the UK’s largest providers for mortgages, savings and current accounts, as well as being a major provider of ISAs, credit cards, personal loans, insurance, and investments.

For one of its business initiatives, Nationwide utilizes AWS Control Tower to build and operate their landing zone which provides a well-established pattern to set up and govern a secure, multi-account AWS environment. Nationwide operates in a highly regulated industry and our governance assurance requires adequate control of any privileged access to production line-of-business data or to resources which have access to them. We chose for this specific business initiative to deploy our landing zone using AWS Organizations, to benefit from ongoing account management and governance as aligned with AWS implementation best practices. We also utilized AWS Single Sign-On (AWS SSO) to create our workforce identities in AWS once and manage access centrally across our AWS Organization. In this blog, we describe the integrations required across AWS Control Tower and AWS SSO to implement a break-glass mechanism that makes access reporting publishable to system operators as well as to internal audit systems and processes. We will outline how we used AWS SSO for our setup as well as the three architecture options we considered, and why we went with the chosen solution.

Sourcing AWS SSO access data for near real-time monitoring

In our setup, we have multiple AWS Accounts and multiple trails on each of these accounts. Users will regularly navigate across multiple accounts as they operate our infrastructure, and their journeys are marked across these multiple trails. Typically, AWS CloudTrail would be our chosen resource to clearly and unambiguously identify account or data access.  The key challenge in this scenario was to design an efficient and cost-effective solution to scan these trails to help identify and report on break-glass user access to account and production data. To address this challenge, we developed the following two architecture design options.

Option 1: A decentralized approach that uses AWS CloudFormation StackSets, Amazon EventBridge and AWS Lambda

Our solution entailed a decentralized approach by deploying a CloudFormation StackSet to create, update, or delete stacks across multiple accounts and AWS Regions with a single operation. The Stackset created Amazon EventBridge rules and target AWS Lambda functions. These functions post to EventBridge in our audit account. Our audit account has a set of Lambda functions running off EventBridge to initiate specific events, format the event message and post to Slack, our centralized communication platform for this implementation. Figure 1 depicts the overall architecture for this option.

De-centralized logging using Amazon EventBridge and AWS Lambda

Figure 1. De-centralized logging using Amazon EventBridge and AWS Lambda

Option 2: Use an organization trail in the Organization Management account

This option uses the centralized organization trail in the Organization Management account to source audit data. Details of how to create an organization trail can be found in the AWS CloudTrail User Guide. CloudTrail was configured to send log events to CloudWatch Logs. These events are then sent via Lambda functions to Slack using webhooks. We used a public terraform module in this GitHub repository to build this Lambda Slack integration. Figure 2 depicts the overall architecture for this option.

Centralized logging pattern using Amazon CloudWatch

Figure 2. Centralized logging pattern using Amazon CloudWatch

This was our preferred option and is the one we finally implemented.

We also evaluated a third option which was to use centralized logging and auditing feature enabled by Control Tower. Users authenticate and federate to target accounts from a central location so it seemed possible to source this info from the centralized logs. These log events arrive as .gz compressed json objects, which meant having to expand these archives repeatedly for inspection. We therefore decided against this option.

A centralized, economic, extensible solution to alert of SSO break-glass

Our requirement was to identify break-glass access across any of the access mechanisms supported by AWS, including CLI and User Portal access. To ensure we have comprehensive coverage across all access mechanisms, we identified all the events initiated for each access mechanism:

  1. User Portal/AWS Console access events
    • Authenticate
    • ListApplications
    • ListApplicationProfiles
    • Federate – this event contains the role that the user is federating into
  2. CLI access events
    • CreateToken
    • ListAccounts
    • ListAccountRoles
    • GetRoleCredentials – this event contains the role that the user is federating into

EventBridge is able to initiate actions after events only when the event is trying to perform changes (when the “readOnly” attribute on the event record body equals “false”).

The AWS support team was aware of this attribute and recommended that we, change the data flow we were using to one able to initiate actions after any kind of event, regardless of the value on its readOnly attribute. The solution in our case was to send the CloudTrail logs to CloudWatch Logs. This then and initiates the Lambda function through a filter subscription that detects the desired event names on the log content.

The filter used is as follows:

{($.eventSource = sso.amazonaws.com) && ($.eventName = Federate||$.eventName = GetRoleCredentials)}

Due to the query size in the CloudWatch Log queries we had to remove the subscription filters and do the parsing of the content of the log lines inside the lambda function. In order to determine what accounts would initiate the notifications, we sent the list of accounts and roles to it as an environment variable at runtime.

Considerations with cross-account SSO access

With direct federation users get an access token. This is most obvious in AWS single sign on at the chiclet page as “Command line or programmatic access”. SSO tokens have a limited lifetime (we use the default 1-hour). A user does not have to get a new token to access a target resource until the one they are using is expired. This means that a user may repeatedly access a target account using the same token during its lifetime. Although the token is made available at the chiclet page, the GetRoleCredentials event does not occur until it is used to authenticate an API call to the target AWS account.


In this blog, we discussed how AWS Control Tower and AWS Single Sign-on enabled Nationwide to build and govern a secure, multi-account AWS environment for one of their business initiatives and centralize access management across our implementation. The integration was important for us to accurately and comprehensively identify and audit break-glass access for our implementation. As a result, we were able to satisfy our security and compliance audit requirements for privileged access to our AWS accounts.

Getting started with AWS SSO delegated administration

Post Syndicated from Chris Mercer original https://aws.amazon.com/blogs/security/getting-started-with-aws-sso-delegated-administration/

Recently, AWS launched the ability to delegate administration of AWS Single Sign-On (AWS SSO) in your AWS Organizations organization to a member account (an account other than the management account). This post will show you a practical approach to using this new feature. For the documentation for this feature, see Delegated administration in the AWS Single Sign-On User Guide.

With AWS Organizations, your enterprise organization can manage your accounts more securely and at scale. One of the benefits of Organizations is that it integrates with many other AWS services, so you can centrally manage accounts and how the services in those accounts can be used.

AWS SSO is where you can create, or connect, your workforce identities in AWS just once, and then manage access centrally across your AWS organization. You can create user identities directly in AWS SSO, or you can bring them from your Microsoft Active Directory or a standards-based identity provider, such as Okta Universal Directory or Azure AD. With AWS SSO, you get a unified administration experience to define, customize, and assign fine-grained access.

By default, the management account in an AWS organization has the power and authority to manage member accounts in the organization. Because of these additional permissions, it is important to exercise least privilege and tightly control access to the management account. AWS recommends that enterprises create one or more accounts specifically designated for security of the organization, with proper controls and access management policies in place. AWS provides a method in which many services can be administered for the organization from a member account; this is usually referred to as a delegated administrator account. These accounts can reside in a security organizational unit (OU), where administrators can enforce organizational policies. Figure 1 is an example of a recommended set of OUs in Organizations.

Figure 1: Recommended AWS Organizations OUs

Figure 1: Recommended AWS Organizations OUs

Many AWS services support this delegated administrator model, including Amazon GuardDuty, AWS Security Hub, and Amazon Macie. For an up-to-date complete list, see AWS services that you can use with AWS Organizations. AWS SSO is now the most recent addition to the list of services in which you can delegate administration of your users, groups, and permissions, including third-party applications, to a member account of your organization.

How to configure a delegated administrator account

In this scenario, your enterprise AnyCompany has an organization consisting of a management account, an account for managing security, as well as a few member accounts. You have enabled AWS SSO in the organization, but you want to enable the security team to manage permissions for accounts and roles in the organization. AnyCompany doesn’t want you to give the security team access to the management account, and they also want to make sure the security team can’t delete the AWS SSO configuration or manage access to that account, so you decide to delegate the administration of AWS SSO to the security account.

Note: There are a few things to consider when making this change, which you should review before you enable delegated administration. These items are covered in the console during the process, and are described in the section Considerations when delegating AWS SSO administration in this post.

To delegate AWS SSO administration to a security account

  1. In the AWS Organizations console, log in to the management account with a user or role that has permission to use organizations:RegisterDelegatedAdministrator, as well as AWS SSO management permissions.
  2. In the AWS SSO console, navigate to the Region in which AWS SSO is enabled.
  3. Choose Settings on the left navigation pane, and then choose the Management tab on the right side.
  4. Under Delegated administrator, choose Register account, as shown in Figure 2.
    Figure 2: The registered account button in AWS SSO

    Figure 2: The Register account button in AWS SSO

  5. Consider the implications of designating a delegated administrator account (as described in the section Considerations when delegating AWS SSO administration). Select the account you want to be able to manage AWS SSO, and then choose Register account, as shown in Figure 3.
    Figure 3: Choosing a delegated administrator account in AWS SSO

    Figure 3: Choosing a delegated administrator account in AWS SSO

You should see a success message to indicate that the AWS SSO delegated administrator account is now setup.

To remove delegated AWS SSO administration from an account

  1. In the AWS Organizations console, log in to the management account with a user or role that has permission to use organizations:DeregisterDelegatedAdministrator.
  2. In the AWS SSO console, navigate to the Region in which AWS SSO is enabled.
  3. Choose Settings on the left navigation pane, and then choose the Management tab on the right side.
  4. Under Delegated administrator, select Deregister account, as shown in Figure 4.
    Figure 4: The Deregister account button in AWS SSO

    Figure 4: The Deregister account button in AWS SSO

  5. Consider the implications of removing a delegated administrator account (as described in the section Considerations when delegating AWS SSO administration), then enter the account name that is currently administering AWS SSO, and choose Deregister account, as shown in Figure 5.
    Figure 5: Considerations of deregistering a delegated administrator in AWS SSO

    Figure 5: Considerations of deregistering a delegated administrator in AWS SSO

Considerations when delegating AWS SSO administration

There are a few considerations you should keep in mind when you delegate AWS SSO administration. The first consideration is that the delegated administrator account will not be able to perform the following actions:

  • Delete the AWS SSO configuration.
  • Delegate (to other accounts) administration of AWS SSO.
  • Manage user or group access to the management account.
  • Manage permission sets that are provisioned (have a user or group assigned) in the organization management account.

For examples of those last two actions, consider the following scenarios:

In the first scenario, you are managing AWS SSO from the delegated administrator account. You would like to give your colleague Saanvi access to all the accounts in the organization, including the management account. This action would not be allowed, since the delegated administrator account cannot manage access to the management account. You would need to log in to the management account (with a user or role that has proper permissions) to provision that access.

In a second scenario, you would like to change the permissions Paulo has in the management account by modifying the policy attached to a ManagementAccountAdmin permission set, which Paulo currently has access to. In this scenario, you would also have to do this from inside the management account, since the delegated administrator account does not have permissions to modify the permission set, because it is provisioned to a user in the management account.

With those caveats in mind, users with proper access in the delegated administrator account will be able to control permissions and assignments for users and groups throughout the AWS organization. For more information about limiting that control, see Allow a user to administer AWS SSO for specific accounts in the AWS Single Sign-On User Guide.

Deregistering an AWS SSO delegated administrator account will not affect any permissions or assignments in AWS SSO, but it will remove the ability for users in the delegated account to manage AWS SSO from that account.

Additional considerations if you use Microsoft Active Directory

There are additional considerations for you to keep in mind if you use Microsoft Active Directory (AD) as an identity provider, specifically if you use AWS SSO configurable AD sync, and which AWS account the directory resides in. In order to use AWS SSO delegated administration when the identity source is set to Active Directory, AWS SSO configurable AD sync must be enabled for the directory. Your organization’s administrators must synchronize Active Directory users and groups you want to grant access to into an AWS SSO identity store. When you enable AWS SSO configurable AD sync, a new feature that launched in April, Active Directory administrators can choose which users and groups get synced into AWS SSO, similar to how other external identity providers work today when using the System for Cross-domain Identity Management (SCIM) v2.0 protocol. This way, AWS SSO knows about users and groups even before they are granted access to specific accounts or roles, and AWS SSO administrators don’t have to manually search for them.

Another thing to consider when delegating AWS SSO administration when using AD as an identity source is where your directory resides, that is which AWS account owns the directory. If you decide to change the AWS SSO identity source from any other source to Active Directory, or change it from Active Directory to any other source, then the directory must reside in (be owned by) the account that the change is being performed in. For example, if you are currently signed in to the management account, you can only change the identity source to or from directories that reside in (are owned by) the management account. For more information, see Manage your identity source in the AWS Single Sign-On User Guide.

Best practices for managing AWS SSO with delegated administration

AWS recommends the following best practices when using delegated administration for AWS SSO:

  • Maintain separate permission sets for use in the organization management account (versus the rest of the accounts). This way, permissions can be kept separate and managed from within the management account without causing confusion among the delegated administrators.
  • When granting access to the organization management account, grant the access to groups (and permission sets) specifically for access in that account. This helps enable the principal of least privilege for this important account, and helps ensure that AWS SSO delegated administrators are able to manage the rest of the organization as efficiently as possible (by reducing the number of users, groups, and permission sets that are off limits to them).
  • If you plan on using one of the AWS Directory Services for Microsoft Active Directory (AWS Managed Microsoft AD or AD Connector) as your AWS SSO identity source, locate the directory and the AWS SSO delegated administrator account in the same AWS account.


In this post, you learned about a helpful new feature of AWS SSO, the ability to delegate administration of your users and permissions to a member account of your organization. AWS recommends as a best practice that the management account of an AWS organization be secured by a least privilege access model, in which as few people as possible have access to the account. You can enable delegated administration for supported AWS services, including AWS SSO, as a useful tool to help your organization minimize access to the management account by moving that control into an AWS account designated specifically for security or identity services. We encourage you to consider AWS SSO delegated administration for administrating access in AWS. To learn more about the new feature, see Delegated administration in the AWS Single Sign-On User Guide.

If you have feedback about this post, submit comments in the Comments section below. If you have questions about this post, start a new thread on the AWS IAM forum or contact AWS Support.

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Chris Mercer

Chris is a security specialist solutions architect. He helps AWS customers implement sophisticated, scalable, and secure solutions to business challenges. He has experience in penetration testing, security architecture, and running military IT systems and networks. Chris holds a Master’s Degree in Cybersecurity, several AWS certifications, OSCP, and CISSP. Outside of AWS, he is a professor, student pilot, and Cub Scout leader.

How to control access to AWS resources based on AWS account, OU, or organization

Post Syndicated from Rishi Mehrotra original https://aws.amazon.com/blogs/security/how-to-control-access-to-aws-resources-based-on-aws-account-ou-or-organization/

AWS Identity and Access Management (IAM) recently launched new condition keys to make it simpler to control access to your resources along your Amazon Web Services (AWS) organizational boundaries. AWS recommends that you set up multiple accounts as your workloads grow, and you can use multiple AWS accounts to isolate workloads or applications that have specific security requirements. By using the new conditions, aws:ResourceOrgID, aws:ResourceOrgPaths, and aws:ResourceAccount, you can define access controls based on an AWS resource’s organization, organizational unit (OU), or account. These conditions make it simpler to require that your principals (users and roles) can only access resources inside a specific boundary within your organization. You can combine the new conditions with other IAM capabilities to restrict access to and from AWS accounts that are not part of your organization.

This post will help you get started using the new condition keys. We’ll show the details of the new condition keys and walk through a detailed example based on the following scenario. We’ll also provide references and links to help you learn more about how to establish access control perimeters around your AWS accounts.

Consider a common scenario where you would like to prevent principals in your AWS organization from adding objects to Amazon Simple Storage Service (Amazon S3) buckets that don’t belong to your organization. To accomplish this, you can configure an IAM policy to deny access to S3 actions unless aws:ResourceOrgID matches your unique AWS organization ID. Because the policy references your entire organization, rather than individual S3 resources, you have a convenient way to maintain this security posture across any number of resources you control. The new conditions give you the tools to create a security baseline for your IAM principals and help you prevent unintended access to resources in accounts that you don’t control. You can attach this policy to an IAM principal to apply this rule to a single user or role, or use service control policies (SCPs) in AWS Organizations to apply the rule broadly across your AWS accounts. IAM principals that are subject to this policy will only be able to perform S3 actions on buckets and objects within your organization, regardless of their other permissions granted through IAM policies or S3 bucket policies.

New condition key details

You can use the aws:ResourceOrgID, aws:ResourceOrgPaths, and aws:ResourceAccount condition keys in IAM policies to place controls on the resources that your principals can access. The following table explains the new condition keys and what values these keys can take.

Condition key Description Operator Single/multi value Value
aws:ResourceOrgID AWS organization ID of the resource being accessed All string operators Single value key Any AWS organization ID
aws:ResourceOrgPaths Organization path of the resource being accessed All string operators Multi-value key Organization paths of AWS organization IDs and organizational unit IDs
aws:ResourceAccount AWS account ID of the resource being accessed All string operators Single value key Any AWS account ID

Note: Of the three keys, only aws:ResourceOrgPaths is a multi-value condition key, while aws:ResourceAccount and aws:ResourceOrgID are single-value keys. For information on how to use multi-value keys, see Creating a condition with multiple keys or values in the IAM documentation.

Resource owner keys compared to principal owner keys

The new IAM condition keys complement the existing principal condition keys aws:PrincipalAccount, aws:PrincipalOrgPaths, and aws:PrincipalOrgID. The principal condition keys help you define which AWS accounts, organizational units (OUs), and organizations are allowed to access your resources. For more information on the principal conditions, see Use IAM to share your AWS resources with groups of AWS accounts in AWS Organizations on the AWS Security Blog.

Using the principal and resource keys together helps you establish permission guardrails around your AWS principals and resources, and makes it simpler to keep your data inside the organization boundaries you define as you continue to scale. For example, you can define identity-based policies that prevent your IAM principals from accessing resources outside your organization (by using the aws:ResourceOrgID condition). Next, you can define resource-based policies that prevent IAM principals outside your organization from accessing resources that are inside your organization boundary (by using the aws:PrincipalOrgID condition). The combination of both policies prevents any access to and from AWS accounts that are not part of your organization. In the next sections, we’ll walk through an example of how to configure the identity-based policy in your organization. For the resource-based policy, you can follow along with the example in An easier way to control access to AWS resources by using the AWS organization of IAM principals on the AWS Security blog.

Setup for the examples

In the following sections, we’ll show an example IAM policy for each of the new conditions. To follow along with Example 1, which uses aws:ResourceAccount, you’ll just need an AWS account.

To follow along with Examples 2 and 3 that use aws:ResourceOrgPaths and aws:ResourceOrgID respectively, you’ll need to have an organization in AWS Organizations and at least one OU created. This blog post assumes that you have some familiarity with the basic concepts in IAM and AWS Organizations. If you need help creating an organization or want to learn more about AWS Organizations, visit Getting Started with AWS Organizations in the AWS documentation.

Which IAM policy type should I use?

You can implement the following examples as identity-based policies, or in SCPs that are managed in AWS Organizations. If you want to establish a boundary for some of your IAM principals, we recommend that you use identity-based policies. If you want to establish a boundary for an entire AWS account or for your organization, we recommend that you use SCPs. Because SCPs apply to an entire AWS account, you should take care when you apply the following policies to your organization, and account for any exceptions to these rules that might be necessary for some AWS services to function properly.

Example 1: Restrict access to AWS resources within a specific AWS account

Let’s look at an example IAM policy that restricts access along the boundary of a single AWS account. For this example, say that you have an IAM principal in account 222222222222, and you want to prevent the principal from accessing S3 objects outside of this account. To create this effect, you could attach the following IAM policy.

  "Version": "2012-10-17",
  "Statement": [
      "Sid": " DenyS3AccessOutsideMyBoundary",
      "Effect": "Deny",
      "Action": [
      "Resource": "*",
      "Condition": {
        "StringNotEquals": {
          "aws:ResourceAccount": [

Note: This policy is not meant to replace your existing IAM access controls, because it does not grant any access. Instead, this policy can act as an additional guardrail for your other IAM permissions. You can use a policy like this to prevent your principals from access to any AWS accounts that you don’t know or control, regardless of the permissions granted through other IAM policies.

This policy uses a Deny effect to block access to S3 actions unless the S3 resource being accessed is in account 222222222222. This policy prevents S3 access to accounts outside of the boundary of a single AWS account. You can use a policy like this one to limit your IAM principals to access only the resources that are inside your trusted AWS accounts. To implement a policy like this example yourself, replace account ID 222222222222 in the policy with your own AWS account ID. For a policy you can apply to multiple accounts while still maintaining this restriction, you could alternatively replace the account ID with the aws:PrincipalAccount condition key, to require that the principal and resource must be in the same account (see example #3 in this post for more details how to accomplish this).

Organization setup: Welcome to AnyCompany

For the next two examples, we’ll use an example organization called AnyCompany that we created in AWS Organizations. You can create a similar organization to follow along directly with these examples, or adapt the sample policies to fit your own organization. Figure 1 shows the organization structure for AnyCompany.

Figure 1: Organization structure for AnyCompany

Figure 1: Organization structure for AnyCompany

Like all organizations, AnyCompany has an organization root. Under the root are three OUs: Media, Sports, and Governance. Under the Sports OU, there are three more OUs: Baseball, Basketball, and Football. AWS accounts in this organization are spread across all the OUs based on their business purpose. In total, there are six OUs in this organization.

Example 2: Restrict access to AWS resources within my organizational unit

Now that you’ve seen what the AnyCompany organization looks like, let’s walk through another example IAM policy that you can use to restrict access to a specific part of your organization. For this example, let’s say you want to restrict S3 object access within the following OUs in the AnyCompany organization:

  • Media
  • Sports
  • Baseball
  • Basketball
  • Football

To define a boundary around these OUs, you don’t need to list all of them in your IAM policy. Instead, you can use the organization structure to your advantage. The Baseball, Basketball, and Football OUs share a parent, the Sports OU. You can use the new aws:ResourceOrgPaths key to prevent access outside of the Media OU, the Sports OU, and any OUs under it. Here’s the IAM policy that achieves this effect.

  "Version": "2012-10-17",
  "Statement": [
      "Sid": " DenyS3AccessOutsideMyBoundary",
      "Effect": "Deny",
      "Action": [
      "Resource": "*",
      "Condition": {
        "ForAllValues:StringNotLike": {
          "aws:ResourceOrgPaths": [

Note: Like the earlier example, this policy does not grant any access. Instead, this policy provides a backstop for your other IAM permissions, preventing your principals from accessing S3 objects outside an OU-defined boundary. If you want to require that your IAM principals consistently follow this rule, we recommend that you apply this policy as an SCP. In this example, we attached this policy to the root of our organization, applying it to all principals across all accounts in the AnyCompany organization.

The policy denies access to S3 actions unless the S3 resource being accessed is in a specific set of OUs in the AnyCompany organization. This policy is identical to Example 1, except for the condition block: The condition requires that aws:ResourceOrgPaths contains any of the listed OU paths. Because aws:ResourceOrgPaths is a multi-value condition, the policy uses the ForAllValues:StringNotLike operator to compare the values of aws:ResourceOrgPaths to the list of OUs in the policy.

The first OU path in the list is for the Media OU. The second OU path is the Sports OU, but it also adds the wildcard character * to the end of the path. The wildcard * matches any combination of characters, and so this condition matches both the Sports OU and any other OU further down its path. Using wildcards in the OU path allows you to implicitly reference other OUs inside the Sports OU, without having to list them explicitly in the policy. For more information about wildcards, refer to Using wildcards in resource ARNs in the IAM documentation.

Example 3: Restrict access to AWS resources within my organization

Finally, we’ll look at a very simple example of a boundary that is defined at the level of an entire organization. This is the same use case as the preceding two examples (restrict access to S3 object access), but scoped to an organization instead of an account or collection of OUs.

  "Version": "2012-10-17",
  "Statement": [
      "Sid": "DenyS3AccessOutsideMyBoundary",
      "Effect": "Deny",
      "Action": [
      "Resource": "arn:aws:s3:::*/*",
      "Condition": {
        "StringNotEquals": {
          "aws:ResourceOrgID": "${aws:PrincipalOrgID}"

Note: Like the earlier examples, this policy does not grant any access. Instead, this policy provides a backstop for your other IAM permissions, preventing your principals from accessing S3 objects outside your organization regardless of their other access permissions. If you want to require that your IAM principals consistently follow this rule, we recommend that you apply this policy as an SCP. As in the previous example, we attached this policy to the root of our organization, applying it to all accounts in the AnyCompany organization.

The policy denies access to S3 actions unless the S3 resource being accessed is in the same organization as the IAM principal that is accessing it. This policy is identical to Example 1, except for the condition block: The condition requires that aws:ResourceOrgID and aws:PrincipalOrgID must be equal to each other. With this requirement, the principal making the request and the resource being accessed must be in the same organization. This policy also applies to S3 resources that are created after the policy is put into effect, so it is simple to maintain the same security posture across all your resources.

For more information about aws:PrincipalOrgID, refer to AWS global condition context keys in the IAM documentation.

Learn more

In this post, we explored the new conditions, and walked through a few examples to show you how to restrict access to S3 objects across the boundary of an account, OU, or organization. These tools work for more than just S3, though: You can use the new conditions to help you protect a wide variety of AWS services and actions. Here are a few links that you may want to look at:

If you have any questions, comments, or concerns, contact AWS Support or start a new thread on the AWS Identity and Access Management forum. Thanks for reading about this new feature. If you have feedback about this post, submit comments in the Comments section below.

Want more AWS Security news? Follow us on Twitter.

Rishi Mehrotra

Rishi Mehrotra

Rishi is a Product Manager in AWS IAM. He enjoys working with customers and influencing products decisions. Prior to Amazon, Rishi worked for enterprise IT customers after receiving engineering degree in computer science. He recently pursued MBA from The University of Chicago Booth School of Business. Outside of work, Rishi enjoys biking, reading, and playing with his kids.


Michael Switzer

Mike is the product manager for the Identity and Access Management service at AWS. He enjoys working directly with customers to identify solutions to their challenges, and using data-driven decision making to drive his work. Outside of work, Mike is an avid cyclist and outdoorsperson. He holds a master’s degree in computational mathematics from the University of Washington.

Minimizing Dependencies in a Disaster Recovery Plan

Post Syndicated from Randy DeFauw original https://aws.amazon.com/blogs/architecture/minimizing-dependencies-in-a-disaster-recovery-plan/

The Availability and Beyond whitepaper discusses the concept of static stability for improving resilience. What does static stability mean with regard to a multi-Region disaster recovery (DR) plan? What if the very tools that we rely on for failover are themselves impacted by a DR event?

In this post, you’ll learn how to reduce dependencies in your DR plan and manually control failover even if critical AWS services are disrupted. As a bonus, you’ll see how to use service control policies (SCPs) to help simulate a Regional outage, so that you can test failover scenarios more realistically.

Failover plan dependencies and considerations

Let’s dig into the DR scenario in more detail. Using Amazon Route 53 for Regional failover routing is a common pattern for DR events. In the simplest case, we’ve deployed an application in a primary Region and a backup Region. We have a Route 53 DNS record set with records for both Regions, and all traffic goes to the primary Region. In an event that triggers our DR plan, we manually or automatically switch the DNS records to direct all traffic to the backup Region.

Relying on an automated health check to control Regional failover can be tricky. A health check might not be perfectly reliable if a Region is experiencing some type of degradation. Often, we prefer to initiate our DR plan manually, which then initiates with automation.

What are the dependencies that we’ve baked into this failover plan? First, Route 53, our DNS service, has to be available. It must continue to serve DNS queries, and we have to be able to change DNS records manually. Second, if we do not have a full set of resources already deployed in the backup Region, we must be able to deploy resources into it.

Both dependencies might violate static stability, because we are relying on resources in our DR plan that might be affected by the outage we’re seeing. Ideally, we don’t want to depend on other services running so we can failover and continue to serve our own traffic. How do we reduce additional dependencies?

Static stability

Let’s look at our first dependency on Route 53 – control planes and data planes. Briefly, a control plane is used to configure resources, and the data plane delivers services (see Understanding Availability Needs for a more complete definition.)

The Route 53 data plane, which responds to DNS queries, is highly resilient across Regions. We can safely rely on it during the failure of any single Region. But let’s assume that for some reason we are not able to call on the Route 53 control plane.

Amazon Route 53 Application Recovery Controller (Route 53 ARC) was built to handle this scenario. It provisions a Route 53 health check that we can manually control with a Route 53 ARC routing control, and is a data plane operation. The Route 53 ARC data plane is highly resilient, using a cluster of five Regional endpoints. You can revise the health check if three of the five Regions are available.

Figure 1. Simple Regional failover scenario using Route 53 Application Recovery Controller

Figure 1. Simple Regional failover scenario using Route 53 Application Recovery Controller

The second dependency, being able to deploy resources into the second Region, is not a concern if we run a fully scaled-out set of resources. We must make sure that our deployment mechanism doesn’t rely only on the primary Region. Most AWS services have Regional control planes, so this isn’t an issue.

The AWS Identity and Access Management (IAM) data plane is highly available in each Region, so you can authorize the creation of new resources as long as you’ve already defined the roles. Note: If you use federated authentication through an identity provider, you should test that the IdP does not itself have a dependency on another Region.

Testing your disaster recovery plan

Once we’ve identified our dependencies, we need to decide how to simulate a disaster scenario. Two mechanisms you can use for this are network access control lists (NACLs) and SCPs. The first one enables us to restrict network traffic to our service endpoints. However, the second allows defining policies that specify the maximum permissions for the target accounts. It also allows us to simulate a Route 53 or IAM control plane outage by restricting access to the service.

For the end-to-end DR simulation, we’ve published an AWS samples repository on GitHub that you can use to deploy. This evaluates Route 53 ARC capabilities if both Route 53 and IAM control planes aren’t accessible.

By deploying test applications across us-east-1 and us-west-1 AWS Regions, we can simulate a real-world scenario that determines the business continuity impact, failover timing, and procedures required for successful failover with unavailable control planes.

Figure 2. Simulating Regional failover using service control policies

Figure 2. Simulating Regional failover using service control policies

Before you conduct the test outlined in our scenario, we strongly recommend that you create a dedicated AWS testing environment with an AWS Organizations setup. Make sure that you don’t attach SCPs to your organization’s root but instead create a dedicated organization unit (OU). You can use this pattern to test SCPs and ensure that you don’t inadvertently lock out users from key services.

Chaos engineering

Chaos engineering is the discipline of experimenting on a system to build confidence in its capability to withstand turbulent production conditions. Chaos engineering and its principles are important tools when you plan for disaster recovery. Even a simple distributed system may be too complex to operate reliably. It can be hard or impossible to plan for every failure scenario in non-trivial distributed systems, because of the number of failure permutations. Chaos experiments test these unknowns by injecting failures (for example, shutting down EC2 instances) or transient anomalies (for example, unusually high network latency.)

In the context of multi-Region DR, these techniques can help challenge assumptions and expose vulnerabilities. For example, what happens if a health check passes but the system itself is unhealthy, or vice versa? What will you do if your entire monitoring system is offline in your primary Region, or too slow to be useful? Are there control plane operations that you rely on that themselves depend on a single AWS Region’s health, such as Amazon Route 53? How does your workload respond when 25% of network packets are lost? Does your application set reasonable timeouts or does it hang indefinitely when it experiences large network latencies?

Questions like these can feel overwhelming, so start with a few, then test and iterate. You might learn that your system can run acceptably in a degraded mode. Alternatively, you might find out that you need to be able to failover quickly. Regardless of the results, the exercise of performing chaos experiments and challenging assumptions is critical when developing a robust multi-Region DR plan.


In this blog, you learned about reducing dependencies in your DR plan. We showed how you can use Amazon Route 53 Application Recovery Controller to reduce a dependency on the Route 53 control plane, and how to simulate a Regional failure using SCPs. As you evaluate your own DR plan, be sure to take advantage of chaos engineering practices. Formulate questions and test your static stability assumptions. And of course, you can incorporate these questions into a custom lens when you run a Well-Architected review using the AWS Well-Architected Tool.

How to automate AWS account creation with SSO user assignment

Post Syndicated from Rafael Koike original https://aws.amazon.com/blogs/security/how-to-automate-aws-account-creation-with-sso-user-assignment/


AWS Control Tower offers a straightforward way to set up and govern an Amazon Web Services (AWS) multi-account environment, following prescriptive best practices. AWS Control Tower orchestrates the capabilities of several other AWS services, including AWS Organizations, AWS Service Catalog, and AWS Single Sign-On (AWS SSO), to build a landing zone very quickly. AWS SSO is a cloud-based service that simplifies how you manage SSO access to AWS accounts and business applications using Security Assertion Markup Language (SAML) 2.0. You can use AWS Control Tower to create and provision new AWS accounts and use AWS SSO to assign user access to those newly-created accounts.

Some customers need to provision tens, if not hundreds, of new AWS accounts at one time and assign access to many users. If you are using AWS Control Tower, doing this requires that you provision an AWS account in AWS Control Tower, and then assign the user access to the AWS account in AWS SSO before moving to the next AWS account. This process adds complexity and time for administrators who manage the AWS environment while delaying users’ access to their AWS accounts.

In this blog post, we’ll show you how to automate creating multiple AWS accounts in AWS Control Tower, and how to automate assigning user access to the AWS accounts in AWS SSO, with the ability to repeat the process easily for subsequent batches of accounts. This solution simplifies the provisioning and assignment processes, while enabling automation for your AWS environment, and allows your builders to start using and experimenting on AWS more quickly.

Services used

This solution uses the following AWS services:

High level solution overview

Figure 1 shows the architecture and workflow of the batch AWS account creation and SSO assignment processes.

Figure 1: Batch AWS account creation and SSO assignment automation architecture and workflow

Figure 1: Batch AWS account creation and SSO assignment automation architecture and workflow

Before starting

This solution is configured to be deployed in the North Virginia Region (us-east-1). But you can change the CloudFormation template to run in any Region that supports all the services required in the solution.

AWS Control Tower Account Factory can take up to 25 minutes to create and provision a new account. During this time, you will be unable to use AWS Control Tower to perform actions such as creating an organizational unit (OU) or enabling a guardrail on an OU. As a recommendation, running this solution during a time period when you do not anticipate using AWS Control Tower’s features is best practice.

Collect needed information

Note: You must have already configured AWS Control Tower, AWS Organizations, and AWS SSO to use this solution.

Before deploying the solution, you need to first collect some information for AWS CloudFormation.

The required information you’ll need to gather in these steps is:

  • AWS SSO instance ARN
  • AWS SSO Identity Store ID
  • Admin email address
  • Amazon S3 bucket
  • AWS SSO user group ARN

Prerequisite information: AWS SSO instance ARN

From the web console

You can find this information under Settings in the AWS SSO web console as shown in Figure 2.

Figure 2: AWS SSO instance ARN

Figure 2: AWS SSO instance ARN

From the CLI

You can also get this information by running the following CLI command using AWS Command Line Interface (AWS CLI):

aws sso-admin list-instances

The output is similar to the following:

    "Instances": [
        "InstanceArn": "arn:aws:sso:::instance/ssoins-abc1234567",
        "IdentityStoreId": "d-123456abcd"

Make a note of the InstanceArn value from the output, as this will be used in the AWS SSO instance ARN.

Prerequisite information: AWS SSO Identity Store ID

This is available from either the web console or the CLI.

From the web console

You can find this information in the same screen as the AWS SSO Instance ARN, as shown in Figure 3.

Figure 3: AWS SSO identity store ID

Figure 3: AWS SSO identity store ID

From the CLI

To find this from the AWS CLI command aws sso-admin list-instances, use the IdentityStoreId from the second key-value pair returned.

Prerequisite information: Admin email address

The admin email address notified when a new AWS account is created.

This email address is used to receive notifications when a new AWS account is created.

Prerequisite information: S3 bucket

The name of the Amazon S3 bucket where the AWS account list CSV files will be uploaded to automate AWS account creation.

This globally unique bucket name will be used to create a new Amazon S3 Bucket, and the automation script will receive events from new objects uploaded to this bucket.

Prerequisite information: AWS SSO user group ARN

Go to AWS SSO > Groups and select the user group whose permission set you would like to assign to the new AWS account. Copy the Group ID from the selected user group. This can be a local AWS SSO user group, or a third-party identity provider-synced user group.

Note: For the AWS SSO user group, there is no AWS CLI equivalent; you need to use the AWS web console to collect this information.

Figure 4: AWS SSO user group ARN

Figure 4: AWS SSO user group ARN

Prerequisite information: AWS SSO permission set

The ARN of the AWS SSO permission set to be assigned to the user group.

From the web console

To view existing permission sets using the AWS SSO web console, go to AWS accounts > Permission sets. From there, you can see a list of permission sets and their respective ARNs.

Figure 5: AWS SSO permission sets list

Figure 5: AWS SSO permission sets list

You can also select the permission set name and from the detailed permission set window, copy the ARN of the chosen permission set. Alternatively, create your own unique permission set to be assigned to the intended user group.

Figure 6: AWS SSO permission set ARN

Figure 6: AWS SSO permission set ARN

From the CLI

To get permission set information from the CLI, run the following AWS CLI command:

aws sso-admin list-permission-sets --instance-arn <SSO Instance ARN>

This command will return an output similar to this:

    "PermissionSets": [

If you can’t determine the details for your permission set from the output of the CLI shown above, you can get the details of each permission set by running the following AWS CLI command:

aws sso-admin describe-permission-set --instance-arn <SSO Instance ARN> --permission-set-arn <PermissionSet ARN>

The output will be similar to this:

    "PermissionSet": {
    "Name": "AWSPowerUserAccess",
    "PermissionSetArn": "arn:aws:sso:::permissionSet/ssoins-abc1234567/ps-abc123def4567890",
    "Description": "Provides full access to AWS services and resources, but does not allow management of Users and groups",
    "CreatedDate": "2020-08-28T11:20:34.242000-04:00",
    "SessionDuration": "PT1H"

The output above lists the name and description of each permission set, which can help you identify which permission set ARN you will use.

Solution initiation

The solution steps are in two parts: the initiation, and the batch account creation and SSO assignment processes.

To initiate the solution

  1. Log in to the management account as the AWS Control Tower administrator, and deploy the provided AWS CloudFormation stack with the required parameters filled out.

    Note: To fill out the required parameters of the solution, refer to steps 1 to 6 of the To launch the AWS CloudFormation stack procedure below.

  2. When the stack is successfully deployed, it performs the following actions to set up the batch process. It creates:
    • The S3 bucket where you will upload the AWS account list CSV file.
    • A DynamoDB table. This table tracks the AWS account creation status.
    • A Lambda function, NewAccountHandler.
    • A Lambda function, CreateManagedAccount. This function is triggered by the entries in the Amazon DynamoDB table and initiates the batch account creation process.
    • An Amazon CloudWatch Events rule to detect the AWS Control Tower CreateManagedAccount lifecycle event.
    • Another Lambda function, CreateAccountAssignment. This function is triggered by AWS Control Tower Lifecycle Events via Amazon CloudWatch Events to assign the AWS SSO Permission Set to the specified User Group and AWS account

To create the AWS Account list CSV file

After you deploy the solution stack, you need to create a CSV file based on this sample.csv and upload it to the Amazon S3 bucket created in this solution. This CSV file will be used to automate the new account creation process.

CSV file format

The CSV file must follow the following format:

Test-account-1,[email protected],[email protected],Fname-1,Lname-1,Test-OU-1,,,
Test-account-2,[email protected],[email protected],Fname-2,Lname-2,Test-OU-2,,,
Test-account-3,[email protected],[email protected],Fname-3,Lname-3,Test-OU-1,,,

Where the first line is the column names, and each subsequent line contains the new AWS accounts that you want to create and automatically assign that SSO user group to the permission set.

CSV fields

AccountName: String between 1 and 50 characters [a-zA-Z0-9_-]
SSOUserEmail: String with more than seven characters and be a valid email address for the primary AWS Administrator of the new AWS account
AccountEmail: String with more than seven characters and be a valid email address not used by other AWS accounts
SSOUserFirstName: String with the first name of the primary AWS Administrator of the new AWS account
SSOUserLastName: String with the last name of the primary AWS Administrator of the new AWS account
OrgUnit: String and must be an existing AWS Organizations OrgUnit
Status: String, for future use
AccountId: String, for future use
ErrorMsg: String, for future use

Figure 7 shows the details that are included in our example for the two new AWS accounts that will be created.

Figure 7: Sample AWS account list CSV

Figure 7: Sample AWS account list CSV

  1. The NewAccountHandler function is triggered from an object upload into the Amazon S3 bucket, validates the input file entries, and uploads the validated input file entries to the Amazon DynamoDB table.
  2. The CreateManagedAccount function queries the DynamoDB table to get the details of the next account to be created. If there is another account to be created, then the batch account creation process moves on to Step 4, otherwise it completes.
  3. The CreateManagedAccount function launches the AWS Control Tower Account Factory product in AWS Service Catalog to create and provision a new account.
  4. After Account Factory has completed the account creation workflow, it generates the CreateManagedAccount lifecycle event, and the event log states if the workflow SUCCEEDED or FAILED.
  5. The CloudWatch Events rule detects the CreateManagedAccount AWS Control Tower Lifecycle Event, and triggers the CreateManagedAccount and CreateAccountAssignment functions, and sends email notification to the administrator via AWS SNS.
  6. The CreateManagedAccount function updates the Amazon DynamoDB table with the results of the AWS account creation workflow. If the account was successfully created, it updates the input file entry in the Amazon DynamoDB table with the account ID; otherwise, it updates the entry in the table with the appropriate failure or error reason.
  7. The CreateAccountAssignment function assigns the AWS SSO Permission Set with the appropriate AWS IAM policies to the User Group specified in the Parameters when launching the AWS CloudFormation stack.
  8. When the Amazon DynamoDB table is updated, the Amazon DynamoDB stream triggers the CreateManagedAccount function for subsequent AWS accounts or when new AWS account list CSV files are updated, then steps 1-9 are repeated.

Upload the CSV file

Once the AWS account list CSV file has been created, upload it into the Amazon S3 bucket created by the stack.

Deploying the solution

To launch the AWS CloudFormation stack

Now that all the requirements and the specifications to run the solution are ready, you can launch the AWS CloudFormation stack:

  1. Open the AWS CloudFormation launch wizard in the console.
  2. In the Create stack page, choose Next.

    Figure 8: Create stack in CloudFormation

    Figure 8: Create stack in CloudFormation

  3. On the Specify stack details page, update the default parameters to use the information you captured in the prerequisites as shown in Figure 9, and choose Next.

    Figure 9: Input parameters into AWS CloudFormation

    Figure 9: Input parameters into AWS CloudFormation

  4. On the Configure stack option page, choose Next.
  5. On the Review page, check the box “I acknowledge that AWS CloudFormation might create IAM resources.” and choose Create Stack.
  6. Once the AWS CloudFormation stack has completed, go to the Amazon S3 web console and select the Amazon S3 bucket that you defined in the AWS CloudFormation stack.
  7. Upload the AWS account list CSV file with the information to create new AWS accounts. See To create the AWS Account list CSV file above for details on creating the CSV file.

Workflow and solution details

When a new file is uploaded to the Amazon S3 bucket, the following actions occur:

  1. When you upload the AWS account list CSV file to the Amazon S3 bucket, the Amazon S3 service triggers an event for newly uploaded objects that invokes the Lambda function NewAccountHandler.
  2. This Lambda function executes the following steps:
    • Checks whether the Lambda function was invoked by an Amazon S3 event, or the CloudFormation CREATE event.
    • If the event is a new object uploaded from Amazon S3, read the object.
    • Validate the content of the CSV file for the required columns and values.
    • If the data has a valid format, insert a new item with the data into the Amazon DynamoDB table, as shown in Figure 10 below.

      Figure 10: DynamoDB table items with AWS accounts details

      Figure 10: DynamoDB table items with AWS accounts details

    • Amazon DynamoDB is configured to initiate the Lambda function CreateManagedAccount when insert, update, or delete items are initiated.
    • The Lambda function CreateManagedAccount checks for update event type. When an item is updated in the table, this item is checked by the Lambda function, and if the AWS account is not created, the Lambda function invokes the AWS Control Tower Account Factory from the AWS Service Catalog to create a new AWS account with the details stored in the Amazon DynamoDB item.
    • AWS Control Tower Account Factory starts the AWS account creation process. When the account creation process completes, the status of Account Factory will show as Available in Provisioned products, as shown in Figure 11.

      Figure 11: AWS Service Catalog provisioned products for AWS account creation

      Figure 11: AWS Service Catalog provisioned products for AWS account creation

    • Based on the Control Tower lifecycle events, the CreateAccountAssignment Lambda function will be invoked when the CreateManagedAccount event is sent to CloudWatch Events. An AWS SNS topic is also triggered to send an email notification to the administrator email address as shown in Figure 12 below.

      Figure 12: AWS email notification when account creation completes

      Figure 12: AWS email notification when account creation completes

    • When invoked, the Lambda function CreateAccountAssignment assigns the AWS SSO user group to the new AWS account with the permission set defined in the AWS CloudFormation stack.

      Figure 13: New AWS account showing user groups with permission sets assigned

      Figure 13: New AWS account showing user groups with permission sets assigned

Figure 13 above shows the new AWS account with the user groups and the assigned permission sets. This completes the automation process. The AWS SSO users that are part of the user group will automatically be allowed to access the new AWS account with the defined permission set.

Handling common sources of error

This solution connects multiple components to facilitate the new AWS account creation and AWS SSO permission set assignment. The correctness of the parameters in the AWS CloudFormation stack is important to make sure that when AWS Control Tower creates a new AWS account, it is accessible.

To verify that this solution works, make sure that the email address is a valid email address, you have access to that email, and it is not being used for any existing AWS account. After a new account is created, it is not possible to change its root account email address, so if you input an invalid or inaccessible email, you will need to create a new AWS account and remove the invalid account.

You can view common errors by going to AWS Service Catalog web console. Under Provisioned products, you can see all of your AWS Control Tower Account Factory-launched AWS accounts.

Figure 14: AWS Service Catalog provisioned product with error

Figure 14: AWS Service Catalog provisioned product with error

Selecting Error under the Status column shows you the source of the error. Figure 15 below is an example of the source of the error:

Figure 15: AWS account creation error explanation

Figure 15: AWS account creation error explanation


In this post, we’ve shown you how to automate batch creation of AWS accounts in AWS Control Tower and batch assignment of user access to AWS accounts in AWS SSO. When the batch AWS accounts creation and AWS SSO user access assignment processes are complete, the administrator will be notified by emails from AWS SNS. We’ve also explained how to handle some common sources of errors and how to avoid them.

As you automate the batch AWS account creation and user access assignment, you can reduce the time you spend on the undifferentiated heavy lifting work, and onboard your users in your organization much more quickly, so they can start using and experimenting on AWS right away.

To learn more about the best practices of setting up an AWS multi-account environment, check out this documentation for more information.

If you have feedback about this post, submit comments in the Comments section below.

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Rafael Koike

Rafael is a Principal Solutions Architect supporting Enterprise customers in SouthEast and part of the Storage TFC. Rafael has a passion to build and his expertise in security, storage, networking and application development have been instrumental to help customers move to the cloud secure and fast. When he is not building he like to do Crossfit and target shooting.

Eugene Toh

Eugene Toh is a Solutions Architect supporting Enterprise customers in the Georgia and Alabama areas. He is passionate in helping customers to transform their businesses and take them to the next level. His area of expertise is in cloud migrations and disaster recovery and he enjoys giving public talks on the latest cloud technologies. Outside of work, he loves trying great food and traveling all over the world.

How to enrich AWS Security Hub findings with account metadata

Post Syndicated from Siva Rajamani original https://aws.amazon.com/blogs/security/how-to-enrich-aws-security-hub-findings-with-account-metadata/

In this blog post, we’ll walk you through how to deploy a solution to enrich AWS Security Hub findings with additional account-related metadata, such as the account name, the Organization Unit (OU) associated with the account, security contact information, and account tags. Account metadata can help you search findings, create insights, and better respond to and remediate findings.

AWS Security Hub ingests findings from multiple AWS services, including Amazon GuardDuty, Amazon Inspector, Amazon Macie, AWS Firewall Manager, AWS Identity and Access Management (IAM) Access Analyzer, and AWS Systems Manager Patch Manager. Findings from each service are normalized into the AWS Security Finding Format (ASFF), so you can review findings in a standardized format and take action quickly. You can use AWS Security Hub to provide a single view of all security-related findings, and to set up alerts, automate remediation, and export specific findings to third‑party incident management systems.

The Security or DevOps teams responsible for investigating, responding to, and remediating Security Hub findings may need additional account metadata beyond the account ID, to determine what to do about the finding or where to route it. For example, determining whether the finding originated from a development or production account can be key to determining the priority of the finding and the type of remediation action needed. Having this metadata information in the finding allows customers to create custom insights in Security Hub to track which OUs or applications (based on account tags) have the most open security issues. This blog post demonstrates a solution to enrich your findings with account metadata to help your Security and DevOps teams better understand and improve their security posture.

Solution Overview

In this solution, you will use a combination of AWS Security Hub, Amazon EventBridge and AWS Lambda to ingest the findings and automatically enrich them with account related metadata by querying AWS Organizations and Account management service APIs. The solution architecture is shown in Figure 1 below:

Figure 1: Solution Architecture and workflow for metadata enrichment

Figure 1: Solution Architecture and workflow for metadata enrichment

The solution workflow includes the following steps:

  1. New findings and updates to existing Security Hub findings from all the member accounts flow into the Security Hub administrator account. Security Hub generates Amazon EventBridge events for the findings.
  2. An EventBridge rule created as part of the solution in the Security Hub administrator account will trigger a Lambda function configured as a target every time an EventBridge notification for a new or updated finding imported into Security Hub matches the EventBridge rule shown below:
      "detail-type": ["Security Hub Findings - Imported"],
      "source": ["aws.securityhub"],
      "detail": {
        "findings": {
          "RecordState": ["ACTIVE"],
          "UserDefinedFields": {
            "findingEnriched": [{
              "exists": false

  3. The Lambda function uses the account ID from the event payload to retrieve both the account information and the alternate contact information from the AWS Organizations and Account management service API. The following code within the helper.py constructs the account_details object representing the account information to enrich the finding:
    def get_account_details(account_id, role_name):
        account_details ={}
        organizations_client = AwsHelper().get_client('organizations')
        response = organizations_client.describe_account(AccountId=account_id)
        account_details["Name"] = response["Account"]["Name"]
        response = organizations_client.list_parents(ChildId=account_id)
        ou_id = response["Parents"][0]["Id"]
        if ou_id and response["Parents"][0]["Type"] == "ORGANIZATIONAL_UNIT":
            response = organizations_client.describe_organizational_unit(OrganizationalUnitId=ou_id)
            account_details["OUName"] = response["OrganizationalUnit"]["Name"]
        elif ou_id:
            account_details["OUName"] = "ROOT"
        if role_name:
            account_client = AwsHelper().get_session_for_role(role_name).client("account")
            account_client = AwsHelper().get_client('account')
            response = account_client.get_alternate_contact(
            if response['AlternateContact']:
                print("contact :{}".format(str(response["AlternateContact"])))
                account_details["AlternateContact"] = response["AlternateContact"]
        except account_client.exceptions.AccessDeniedException as error:
            #Potentially due to calling alternate contact on Org Management account
        response = organizations_client.list_tags_for_resource(ResourceId=account_id)
        results = response["Tags"]
        while "NextToken" in response:
            response = organizations_client.list_tags_for_resource(ResourceId=account_id, NextToken=response["NextToken"])
        account_details["tags"] = results
        AccountHelper.logger.info("account_details: %s" , str(account_details))
        return account_details

  4. The Lambda function updates the finding using the Security Hub BatchUpdateFindings API to add the account related data into the Note and UserDefinedFields attributes of the SecurityHub finding:
    #lookup and build the finding note and user defined fields  based on account Id
    enrichment_text, tags_dict = enrich_finding(account_id, assume_role_name)
    logger.debug("Text to post: %s" , enrichment_text)
    logger.debug("User defined Fields %s" , json.dumps(tags_dict))
    #add the Note to the finding and add a userDefinedField to use in the event bridge rule and prevent repeat lookups
    response = secHubClient.batch_update_findings(
                'Id': enrichment_finding_id,
                'ProductArn': enrichment_finding_arn
            'Text': enrichment_text,
            'UpdatedBy': enrichment_author

    Note: All state change events published by AWS services through Amazon Event Bridge are free of cost. The AWS Lambda free tier includes 1M free requests per month, and 400,000 GB-seconds of compute time per month at the time of publication of this post. If you process 2M requests per month, the estimated cost for this solution would be approximately $7.20 USD per month.

  5. Prerequisites

    1. Your AWS organization must have all features enabled.
    2. This solution requires that you have AWS Security Hub enabled in an AWS multi-account environment which is integrated with AWS Organizations. The AWS Organizations management account must designate a Security Hub administrator account, which can view data from and manage configuration for its member accounts. Follow these steps to designate a Security Hub administrator account for your AWS organization.
    3. All the members accounts are tagged per your organization’s tagging strategy and their security alternate contact is filled. If the tags or alternate contacts are not available, the enrichment will be limited to the Account Name and the Organizational Unit name.
    4. Trusted access must be enabled with AWS Organizations for AWS Account Management service. This will enable the AWS Organizations management account to call the AWS Account Management API operations (such as GetAlternateContact) for other member accounts in the organization. Trusted access can be enabled either by using AWS Management Console or by using AWS CLI and SDKs.

      The following AWS CLI example enables trusted access for AWS Account Management in the calling account’s organization.

      aws organizations enable-aws-service-access --service-principal account.amazonaws.com

    5. An IAM role with a read only access to lookup the GetAlternateContact details must be created in the Organizations management account, with a trust policy that allows the Security Hub administrator account to assume the role.

    Solution Deployment

    This solution consists of two parts:

    1. Create an IAM role in your Organizations management account, giving it necessary permissions as described in the Create the IAM role procedure below.
    2. Deploy the Lambda function and the other associated resources to your Security Hub administrator account

    Create the IAM role

    Using console, AWS CLI or AWS API

    Follow the Creating a role to delegate permissions to an IAM user instructions to create a IAM role using the console, AWS CLI or AWS API in the AWS Organization management account with role name as account-contact-readonly, based on the trust and permission policy template provided below. You will need the account ID of your Security Hub administrator account.

    The IAM trust policy allows the Security Hub administrator account to assume the role in your Organization management account.

    IAM Role trust policy

      "Version": "2012-10-17",
      "Statement": [
          "Effect": "Allow",
          "Principal": {
            "AWS": "arn:aws:iam::<SH administrator Account ID>:root"
          "Action": "sts:AssumeRole",
          "Condition": {}

    Note: Replace the <SH Delegated Account ID> with the account ID of your Security Hub administrator account. Once the solution is deployed, you should update the principal in the trust policy shown above to use the new IAM role created for the solution.

    IAM Permission Policy

        "Version": "2012-10-17",
        "Statement": [
                "Effect": "Allow",
                "Action": [
                "Resource": "arn:aws:account::<Org. Management Account id>:account/o-*/*"

    The IAM permission policy allows the Security Hub administrator account to look up the alternate contact information for the member accounts.

    Make a note of the Role ARN for the IAM role similar to this format:

    arn:aws:iam::<Org. Management Account id>:role/account-contact-readonly. 

    You will need this while the deploying the solution in the next procedure.

    Using AWS CloudFormation

    Alternatively, you can use the  provided CloudFormation template to create the role in the management account. The IAM role ARN is available in the Outputs section of the created CloudFormation stack.

    Deploy the Solution to your Security Hub administrator account

    You can deploy the solution using either the AWS Management Console, or from the GitHub repository using the AWS SAM CLI.

    Note: if you have designated an aggregation Region within the Security Hub administrator account, you can deploy this solution only in the aggregation Region, otherwise you need to deploy this solution separately in each Region of the Security Hub administrator account where Security Hub is enabled.

    To deploy the solution using the AWS Management Console

    1. In your Security Hub administrator account, launch the template by choosing the Launch Stack button below, which creates the stack the in us-east-1 Region.

      Note: if your Security Hub aggregation region is different than us-east-1 or want to deploy the solution in a different AWS Region, you can deploy the solution from the GitHub repository described in the next section.

      Select this image to open a link that starts building the CloudFormation stack

    2. On the Quick create stack page, for Stack name, enter a unique stack name for this account; for example, aws-security-hub–findings-enrichment-stack, as shown in Figure 2 below.
      Figure 2: Quick Create CloudFormation stack for the Solution

      Figure 2: Quick Create CloudFormation stack for the Solution

    3. For ManagementAccount, enter the AWS Organizations management account ID.
    4. For OrgManagementAccountContactRole, enter the role ARN of the role you created previously in the Create IAM role procedure.
    5. Choose Create stack.
    6. Once the stack is created, go to the Resources tab and take note of the name of the IAM Role which was created.
    7. Update the principal element of the IAM role trust policy which you previously created in the Organization management account in the Create the IAM role procedure above, replacing it with the role name you noted down, as shown below.
      Figure 3 Update Management Account Role’s Trust

      Figure 3 Update Management Account Role’s Trust

    To deploy the solution from the GitHub Repository and AWS SAM CLI

    1. Install the AWS SAM CLI
    2. Download or clone the github repository using the following commands
      $ git clone https://github.com/aws-samples/aws-security-hub-findings-account-data-enrichment.git
      $ cd aws-security-hub-findings-account-data-enrichment

    3. Update the content of the profile.txt file with the profile name you want to use for the deployment
    4. To create a new bucket for deployment artifacts, run create-bucket.sh by specifying the region as argument as below.
      $ ./create-bucket.sh us-east-1

    5. Deploy the solution to the account by running the deploy.sh script by specifying the region as argument
      $ ./deploy.sh us-east-1

    6. Once the stack is created, go to the Resources tab and take note of the name of the IAM Role which was created.
    7. Update the principal element of the IAM role trust policy which you previously created in the Organization management account in the Create the IAM role procedure above, replacing it with the role name you noted down, as shown below.
      "AWS": "arn:aws:iam::<SH Delegated Account ID>: role/<Role Name>"

    Using the enriched attributes

    To test that the solution is working as expected, you can create a standalone security group with an ingress rule that allows traffic from the internet. This will trigger a finding in Security Hub, which will be populated with the enriched attributes. You can then use these enriched attributes to filter and create custom insights, or take specific response or remediation actions.

    To generate a sample Security Hub finding using AWS CLI

    1. Create a Security Group using following AWS CLI command:
      aws ec2 create-security-group --group-name TestSecHubEnrichmentSG--description "Test Security Hub enrichment function"

    2. Make a note of the security group ID from the output, and use it in Step 3 below.
    3. Add an ingress rule to the security group which allows unrestricted traffic on port 100:
      aws ec2 authorize-security-group-ingress --group-id <Replace Security group ID> --protocol tcp --port 100 --cidr

    Within few minutes, a new finding will be generated in Security Hub, warning about the unrestricted ingress rule in the TestSecHubEnrichmentSG security group. For any new or updated findings which do not have the UserDefinedFields attribute findingEnriched set to true, the solution will enrich the finding with account related fields in both the Note and UserDefinedFields sections in the Security Hub finding.

    To see and filter the enriched finding

    1. Go to Security Hub and click on Findings on the left-hand navigation.
    2. Click in the filter field at the top to add additional filters. Choose a filter field of AWS Account ID, a filter match type of is, and a value of the AWS Account ID where you created the TestSecHubEnrichmentSG security group.
    3. Add one more filter. Choose a filter field of Resource type, a filter match type of is, and the value of AwsEc2SecurityGroup.
    4. Identify the finding for security group TestSecHubEnrichmentSG with updates to Note and UserDefinedFields, as shown in Figures 4 and 5 below:
      Figure 4: Account metadata enrichment in Security Hub finding’s Note field

      Figure 4: Account metadata enrichment in Security Hub finding’s Note field

      Figure 5: Account metadata enrichment in Security Hub finding’s UserDefinedFields field

      Figure 5: Account metadata enrichment in Security Hub finding’s UserDefinedFields field

      Note: The actual attributes you will see as part of the UserDefinedFields may be different from the above screenshot. Attributes shown will depend on your tagging configuration and the alternate contact configuration. At a minimum, you will see the AccountName and OU fields.

    5. Once you confirm that the solution is working as expected, delete the stand-alone security group TestSecHubEnrichmentSG, which was created for testing purposes.

    Create custom insights using the enriched attributes

    You can use the attributes available in the UserDefinedFields in the Security Hub finding to filter the findings. This lets you generate custom Security Hub Insight and reports tailored to suit your organization’s needs. The example shown in Figure 6 below creates a custom Security Hub Insight for findings grouped by severity for a specific owner, using the Owner attribute within the UserDefinedFields object of the Security Hub finding.

    Figure 6: Custom Insight with Account metadata filters

    Figure 6: Custom Insight with Account metadata filters

    Event Bridge rule for response or remediation action using enriched attributes

    You can also use the attributes in the UserDefinedFields object of the Security Hub finding within the EventBridge rule to take specific response or remediation actions based on values in the attributes. In the example below, you can see how the Environment attribute can be used within the EventBridge rule configuration to trigger specific actions only when value matches PROD.

      "detail-type": ["Security Hub Findings - Imported"],
      "source": ["aws.securityhub"],
      "detail": {
        "findings": {
          "RecordState": ["ACTIVE"],
          "UserDefinedFields": {
            "Environment": "PROD"


    This blog post walks you through a solution to enrich AWS Security Hub findings with AWS account related metadata using Amazon EventBridge notifications and AWS Lambda. By enriching the Security Hub findings with account related information, your security teams have better visibility, additional insights and improved ability to create targeted reports for specific account or business teams, helping them prioritize and improve overall security response. To learn more, see:

If you have feedback about this post, submit comments in the Comments section below. If you have any questions about this post, start a thread on the AWS Security Hub forum.

Want more AWS Security news? Follow us on Twitter.

Siva Rajamani

Siva Rajamani

Siva Rajamani is a Boston-based Enterprise Solutions Architect at AWS. Siva enjoys working closely with customers to accelerate their AWS cloud adoption and improve their overall security posture.

Prashob Krishnan

Prashob Krishnan

Prashob Krishnan is a Denver-based Technical Account Manager at AWS. Prashob is passionate about security. He enjoys working with customers to solve their technical challenges and help build a secure scalable architecture on the AWS Cloud.

Find Public IPs of Resources – Use AWS Config for Vulnerability Assessment

Post Syndicated from Gurkamal Deep Singh Rakhra original https://aws.amazon.com/blogs/architecture/find-public-ips-of-resources-use-aws-config-for-vulnerability-assessment/

Systems vulnerability management is a key component of your enterprise security program. Its goal is to remediate OS, software, and applications vulnerabilities. Scanning tools can help identify and classify these vulnerabilities to keep the environment secure and compliant.

Typically, vulnerability scanning tools operate from internal or external networks to discover and report vulnerabilities. For internal scanning, the tools use private IPs of target systems in scope. For external scans, the public target system’s IP addresses are used. It is important that security teams always maintain an accurate inventory of all deployed resource’s IP addresses. This ensures a comprehensive, consistent, and effective vulnerability assessment.

This blog discusses a scalable, serverless, and automated approach to discover public IP addresses assigned to resources in a single or multi-account environment in AWS, using AWS Config.

Single account is when you have all your resources in a single AWS account. A multi-account environment refers to many accounts under the same AWS Organization.

Understanding scope of solution

You may have good visibility into the private IPs assigned to your resources: Amazon Elastic Compute Cloud (Amazon EC2), Amazon Elastic Kubernetes Service (EKS) clusters, Elastic Load Balancing (ELB), and Amazon Elastic Container Service (Amazon ECS). But it may require some effort to establish a complete view of the existing public IPs. And these IPs can change over time, as new systems join and exit the environment.

An elastic network interface is a logical networking component in a Virtual Private Cloud (VPC) that represents a virtual network card. The elastic network interface routes traffic to other destinations/resources. Usually, you have to make Describe* API calls for the specific resource with an elastic network interface to get information about its configuration and IP address. This may throttle the resource-specific API calls, and result in higher costs. Additionally, if there are tens or hundreds of accounts, it becomes exponentially more difficult to get the information into a single inventory.

AWS Config enables you to assess, audit, and evaluate the configurations of your AWS resources. The advanced query feature provides a single query endpoint and language to get current resource state metadata for a single account and Region, or multiple accounts and Regions. You can use configuration aggregators to run the same queries from a central account across multiple accounts and AWS Regions.

AWS Config supports a subset of structured query language (SQL) SELECT syntax, which enables you to perform property-based queries and aggregations on the current configuration item (CI) data. Advanced query is available at no additional cost to AWS Config customers in all AWS Regions (except China Regions) and AWS GovCloud (US).

AWS Organizations helps you centrally govern your environment. Its integration with other AWS services lets you define central configurations, security mechanisms, audit requirements, and resource sharing across accounts in your organization.

Choosing scope of advanced queries in AWS Config

When running advanced queries in AWS Config, you must choose the scope of the query. The scope defines the accounts you want to run the query against and is configured when you create an aggregator.

Following are the three possible scopes when running advanced queries:

  1. Single account and single Region
  2. Multiple accounts and multiple Regions
  3. AWS Organization accounts

Single account and single Region

Figure 1. AWS Config workflow for single account and single Region

Figure 1. AWS Config workflow for single account and single Region

The use case shown in Figure 1 addresses the need of customers operating within a single account and single Region. With AWS Config enabled for the individual account, you will use AWS Config advanced query feature to run SQL queries. These will give you resource metadata about associated public IPs. You do not require an aggregator for single-account and single Region.

In Figure 1.1, the advanced query returned results from a single account and all Availability Zones within the Region in which the query was run.

Figure 1.1 Advanced query returning results for a single account and single Region

Figure 1.1 Advanced query returning results for a single account and single Region

Query for reference










  AND configuration.association.publicIp>''

This query is fetching the properties of all elastic network interfaces. The WHERE condition is used to list the elastic network interfaces using the resourceType property and find all public IPs greater than This is because elastic network interfaces can exist with a private IP, in which case there will be no public IP assigned to it. For a list of supported resourceType, refer to supported resource types for AWS Config.

Multiple accounts and multiple Regions

Figure 2. AWS Config monitoring workflow for multiple account and multiple Regions. The figure shows EC2, EKS, and Amazon ECS, but it can be any AWS resource having a public elastic network interface.

Figure 2. AWS Config monitoring workflow for multiple account and multiple Regions. The figure shows EC2, EKS, and Amazon ECS, but it can be any AWS resource having a public elastic network interface.

AWS Config enables you to monitor configuration changes against multiple accounts and multiple Regions via an aggregator, see Figure 2. An aggregator is an AWS Config resource type that collects AWS Config data from multiple accounts and Regions. You can choose the aggregator scope when running advanced queries in AWS Config. Remember to authorize the aggregator accounts to collect AWS Config configuration and compliance data.

Figure 2.1 Advanced query returning results from multiple Regions (awsRegion column) as highlighted in the diagram

Figure 2.1 Advanced query returning results from multiple Regions (awsRegion column) as highlighted in the diagram

This use case applies when you have AWS resources in multiple accounts (or span multiple organizations) and multiple Regions. Figure 2.1 shows the query results being returned from multiple AWS Regions.

Accounts in AWS Organization

Figure 3. The workflow of accounts in an AWS Organization being monitored by AWS Config. This figure shows EC2, EKS, and Amazon ECS but it can be any AWS resource having a public elastic network interface.

Figure 3. The workflow of accounts in an AWS Organization being monitored by AWS Config. This figure shows EC2, EKS, and Amazon ECS but it can be any AWS resource having a public elastic network interface.

An aggregator also enables you to monitor all the accounts in your AWS Organization, see Figure 3. When this option is chosen, AWS Config enables you to run advanced queries against the configuration history in all the accounts in your AWS Organization. Remember that an aggregator will only aggregate data from the accounts and Regions that are specified when the aggregator is created.

Figure 3.1 Advanced query returning results from all accounts (accountId column) under an AWS Organization

Figure 3.1 Advanced query returning results from all accounts (accountId column) under an AWS Organization

In Figure 3.1, the query is run against all accounts in an AWS Organization. This scope of AWS Organization is accomplished by the aggregator and it automatically accumulates data from all accounts under a specific AWS Organization.

Common architecture workflow for discovering public IPs

Figure 4. High-level architecture pattern for discovering public IPs

Figure 4. High-level architecture pattern for discovering public IPs

The workflow shown in Figure 4 starts with Amazon EventBridge triggering an AWS Lambda function. You can configure an Amazon EventBridge schedule via rate or cron expressions, which define the frequency. This AWS Lambda function will host the code to make an API call to AWS Config that will run an advanced query. The advanced query will check for all elastic network interfaces in your account(s). This is because any public resource launched in your account will be assigned an elastic network interface.

When the results are returned, they can be stored on Amazon S3. These result files can be timestamped (via naming or S3 versioning) in order to keep a history of public IPs used in your account. The result set can then be fed into or accessed by the vulnerability scanning tool of your choice.

Note: AWS Config advanced queries can also be used to query IPv6 addresses. You can use the “configuration.ipv6Addresses” AWS Config property to get IPv6 addresses. When querying IPv6 addresses, remove “configuration.association.publicIp > ‘’” condition from the preceding sample queries. For more information on available AWS Config properties and data types, refer to GitHub.


In this blog, we demonstrated how to extract public IP information from resources deployed in your account(s) using AWS Config and AWS Config advanced query. We discussed how you can support your vulnerability scanning process by identifying public IPs in your account(s) that can be fed into your scanning tool. This solution is serverless, automated, and scalable, which removes the undifferentiated heavy lifting required to manage your resources.

Learn more about AWS Config best practices:

Simplify setup of Amazon Detective with AWS Organizations

Post Syndicated from Karthik Ram original https://aws.amazon.com/blogs/security/simplify-setup-of-amazon-detective-with-aws-organizations/

Amazon Detective makes it easy to analyze, investigate, and quickly identify the root cause of potential security issues or suspicious activities by collecting log data from your AWS resources. Amazon Detective simplifies the process of a deep dive into a security finding from other AWS security services, such as Amazon GuardDuty and AWS SecurityHub. Detective uses machine learning, statistical analysis, and graph theory to build a linked set of data that enables customers to easily conduct faster and more efficient security investigations.

In this post you will learn about the new AWS Organizations integration with Amazon Detective, where new and existing Detective customers can delegate any account in their organization to be the delegated Detective administrator account, and can centrally manage the Detective behavior graph database for an organization with up to 1,200 accounts.

Customers tell us that they want to manage security findings and investigations across multiple AWS Accounts. Depending on the customer this can be 100s or 1000s of accounts. AWS Organizations integration with security services, including GuardDuty, Security Hub and AWS IAM Access Analyzer comes in handy by helping customers centralize management and governance of their environments as they scale and grow their AWS accounts and resources. Adding to the list, Detective is now integrated with AWS Organizations to simplify security posture management across all existing and future AWS accounts across an organization. Organizations integration is available in all AWS Regions that Detective supports.

Detective is aware of your existing delegated administrator accounts for other AWS Security services such as GuardDuty or Security Hub. Using this awareness, Detective recommends that you choose the same account as the administrator account for Detective, as shown in Figure 1. For a more complete walk though of how to enable your accounts, visit the AWS Detective Documentation.

Figure 1. Setting delegated administrator

Figure 1. Setting delegated administrator

You can then use the same account to manage all of your security services. AWS recommends you align your Detective administrator account with your GuardDuty and SecurityHub administrator accounts, to enable seamless integration between Detective and those services.

  • In GuardDuty or Security Hub, when viewing details for a GuardDuty finding, you can pivot from the finding details to the Detective finding profile.
  • In Detective, when investigating a GuardDuty finding, you can choose the option to archive that finding.

Once designated, the chosen account becomes the administrator account for the organization behavior graph. They can enable any organization account as a member account in the organization behavior graph, and can configure Detective to automatically enable organization accounts when they join the organization.

Figure 2. Auto-enabling Organization accounts

Figure 2. Auto-enabling Organization accounts

The Detective administrator account can also manually invite other accounts to join the organization behavior graph.

Figure 3. Inviting accounts to join the Organization behavior graph

Figure 3. Inviting accounts to join the Organization behavior graph

From Detective, the administrator account can centrally conduct security investigations across the organization

Considerations for AWS Organizations support

Some considerations and recommendations around Organizations support for Detective:

  1. Detective allows up to 1,200 member accounts in each behavior graph.
  2. The Detective administrator account becomes the administrator account for the organization’s behavior graph.
  3. An account can be a member account of multiple behavior graphs in the same Region. An account can accept multiple invitations. An organization account can be enabled as a member account in the organization behavior graph, and can then also accept invitations to other behavior graphs.
  4. An account can only be the administrator account of one behavior graph per Region, but can be an administrator account in different Regions.
  5. Changes to an organization are not immediately reflected in Detective. For most changes, such as new and removed organization accounts, it can take up to an hour for Detective to be notified.

Other recent updates from Amazon Detective

Additional support for all GuardDuty findings

With the recent expansion of security investigation support for Amazon Simple Storage Service (S3) and DNS-related findings on Amazon GuardDuty, Amazon Detective now provides full coverage of all detections from GuardDuty. Security analysts can now easily investigate and analyze the root cause of all GuardDuty findings using Detective, using the Investigate in Detective option in GuardDuty and Security Hub for further investigation.

New resource focused view

In addition to these integrations with AWS Organization and GuardDuty, Detective now makes it even easier for a security analyst to investigate entities and behaviors using a revamped user experience as seen in Figure 4. Amazon Detective presents a unified view of user and resource interactions over time, with all the context and details in one place, to help you quickly analyze the root cause of a security finding.

Figure 4. New resource focused view

Figure 4. New resource focused view

New finding overview

The new finding overview provides an expanded set of details for each finding, and provides links to the profiles for each involved entity as seen in the right panel in Figure 4. With this unified view, you can visualize all of the details and context in one place, while identifying the underlying reasons for the findings. This resource-focused view helps you understand the connections between resources affected by a security finding, and further helps you drill down into relevant historical activity to quickly determine the root cause.

Integration with Splunk

Amazon Detective, in coordination with the Splunk Trumpet project, has released the ability to pivot from an Amazon GuardDuty finding in Splunk directly to an Amazon Detective entity profile. Customers can now quickly identify the root cause of potential security issues or suspicious activities. This setting can be enabled on the Splunk Trumpet project installation page by selecting Detective GuardDuty URLs from the AWS CloudWatch Events dropdown.

Amazon Detective’s interactive visualizations make it easy to investigate and analyze issues more thoroughly and effectively, with minimal effort. Using these visualizations, customers can easily filter large sets of event data into specific timelines, with all the details, context, and guidance needed to help you to investigate quickly. For example; Amazon Detective enables you to view login attempts on a geolocation map, drill down into relevant historical activity, quickly determine a root cause, and if necessary, take action to resolve the issue.

Amazon Detective makes it easy to analyze, investigate, and quickly identify the root cause of potential security issues. To get started, enable a 30-day free trial of Amazon Detective with just a few clicks in the AWS Management console. See the AWS Regions page for a list of all Regions where Detective is available. To learn more, visit the Amazon Detective product page.

If you have feedback about this post, submit comments in the Comments section below.

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Karthik Ram

Karthik Ram

Karthik is a Senior Solutions Architect with Amazon Web Services based in Columbus, Ohio. He has a background in Networking and Infrastructure architecture. At AWS, Karthik helps customers build secure and innovative cloud solutions, solving their business problems using data driven approaches. Karthik’s Area of Depth is Cloud Security with a focus on Threat Detection and Incident Response (TDIR).


Ross Warren

Ross Warren is a Senior Solution Architect at AWS based in Northern Virginia. Prior to his work at AWS, Ross’ areas of focus included cyber threat hunting and security operations. Ross has worked at a handful of startups and has enjoyed the transition to AWS because he can continue to build solutions for customers on today’s most innovative platform.

Get started with AWS DevOps Guru Multi-Account Insight Aggregation with AWS Organizations

Post Syndicated from Ifeanyi Okafor original https://aws.amazon.com/blogs/devops/get-started-with-aws-devops-guru-multi-account-insight-aggregation-with-aws-organizations/

Amazon DevOps Guru is a fully managed service that uses machine learning (ML) to continuously analyze and consolidate operational data streams from multiple sources, such as Amazon CloudWatch metrics, AWS Config, AWS CloudFormation, AWS X-Ray, and provide you with a single console dashboard. This dashboard helps customers improve operational performance and avoid expensive downtime by generating actionable insights that flag operational anomalies, identify the likely root cause, and recommend corrective actions.

As customers scale their AWS resources across multiple accounts and deploy DevOps Guru across applications and use cases on these accounts, they get a siloed view of the operational health of their applications. Now you can enable multi-account support with AWS Organizations and designate a member account to manage operational insights across your entire organization. This delegated administrator can get a holistic view of the operational health of their applications across the organization—without the need for any additional customization.

In this post, we will walk through the process of setting up a delegated administrator. We will also explore how to monitor insights across your entire organization from this account.

Overview of the multi-account environment

The multi-account environment operates based on the organizational hierarchy that your organization has defined in AWS Organizations. This AWS service helps you centrally manage and govern your cloud environment. For this reason, you must have an organization set up in AWS Organizations before you can implement multi-account insights visibility. AWS Organizations is available to all AWS customers at no additional charge, and the service user guide has instructions for creating and configuring an organization in your AWS environment.

Understanding the management account, a delegated administrator, and other member accounts is fundamental to the multi-account visibility functionality in DevOps Guru. Before proceeding further, let’s recap these terms.

  • A management account is the AWS account you use to create your organization. You can create other accounts in your organization, invite and manage invitations for other existing accounts to join your organization, and remove accounts from your organization. The management account has wide permissions and access to accounts within the organization. It should only be used for absolutely essential administrative tasks, such as managing accounts, OUs, and organization-level policies. You can refer to the AWS Organizations FAQ for more information on management accounts.
  • When the management account gives a member account service-level administrative permissions, it becomes a delegated administrator. Because the permissions are assigned at the service level, delegated administrator’s privileges are confined to the AWS service in question (DevOps Guru, in this case). The delegated administrator manages the service on behalf of the management account, leaving the management account to focus on administrative tasks, such as account and policy management. Currently, DevOps Guru supports a single delegated administrator, which operates at the root level (i.e., at the organization level). When elevating a member account to a delegated administrator, it must be in the organization. For more information about adding a member account to an organization, see inviting an AWS account to join your organization.
  • Member accounts are accounts without any administrative privilege. An account can be a member of only one organization at a time.


You must have the following to enable multi-account visibility:

  • An organization already set up in AWS Organizations. AWS Organizations is available to all AWS customers at no additional charge, and the service user guide has instructions for creating and configuring an organization in your AWS environment.
  • A member account that is in your organization and already onboarded in DevOps Guru. This account will be registered as a delegated administrator. For more information about adding a member account to an organization, see inviting an AWS account to join your organization.

Setting up multi-account insights visibility in your organization

In line with AWS Organizations’ best practices, we recommend first assigning a delegated administrator. Although a management account can view DevOps Guru insights across the organization, management accounts should be reserved for organization-level management, while the delegated administrator manages at the service level.

Registering a Delegated Administrator

A delegated administrator must be registered by the management account. The steps below assume that you have a member account to register as a delegated administrator. If your preferred account is not yet in your organization, then invite the account to join your organization.

To register a delegated administrator

  1. Log in to the DevOps Guru Console with the management account.
  2. On the welcome page, under Set up type, select Monitor applications across your organizations. If you select Monitor applications in the current AWS account, then your dashboard will display insights for the management account.
  3. Under Delegated administrator, select Register a delegated administrator (Recommended).
  4. Select Register delegated administrator to complete the process.

Register a delegated administrator. Steps 1-4 highlighted in console screenshot.

To de-register a delegated administrator

  1. Log in to the DevOps Guru Console and navigate to the Management account
  2. On the Management account page, select De-register administrator.

De-register a delegated Administrator. Steps 1 and 2 highlighted on console.

Viewing insights as a Delegated Administrator

As the delegated administrator, you can choose to view insights from

  • specific accounts
  • specific OUs
  • the entire organization

To view insights from specific accounts

  1. Log in to the DevOps Guru console, and select Accounts from the dropdown menu on the dashboard.
  2. Select the search bar to display a list of member accounts.
  3. Select up to five accounts, and select anywhere outside the dropdown menu to apply your selection. Simply select the delegated administrator account from the dropdown menu to view insights from the delegated administrator account.

View Insights from specific account. Steps 1-3 highlighted on dashboard screenshot.

The system health summary now will display information for the selected accounts.

To view insights from specific organizational units

  1. Log in to the DevOps Guru console, and select Organizational Units from the dropdown menu on the dashboard.
  2. Select the search bar to display the list of OUs.
  3. Select up to five OUs, and select anywhere outside of the dropdown menu to apply your selection.

View insights from specific organizational units. Steps 1-3 highlighted in dashboard screenshot.

Now the system health summary will display information for the selected OUs. Nested OUs are currently not supported, so only the accounts directly under the OU are included when an OU is selected. Select the sub-OU in addition to the parent OU to include accounts in a sub-OU,.

To view insights across the entire organization

  1. Log in to the DevOps Guru console and navigate to the Insights
  2. On the Reactive tab, you can see a list of all the reactive insights in the organization. On the Proactive tab, you can also see a list of all the proactive insights in the organization. You will notice that the table displaying the insights now has an Account ID column (highlighted in the snapshot below). This table aggregates insights from different accounts in the organization.

View insights across the entire organization.

  1. Use one or more of the following filters to find the insights that you are looking for
    1. Choose the Reactive or Proactive
    2. In the search bar, you can add an account ID, status, severity, stack, or resource name to specify a filter.

View insights across the entire organization and filter. Steps 1-3 highlighted in Insights summary page.

    1. To search by account ID, select the search bar, select Account, then select an account ID in the submenu.
    2. Choose or specify a time range to filter by insight creation time. For example, 12h shows insights created in the past 12 hours, and 1d shows the insights of the previous day. 1w will show the past week’s insights, and 1m will show the last month’s insights. Custom lets you specify another time range. The maximum time range you can use to filter insights is 180 days.

View insights across the entire organization and fitler by time.

Viewing insights from the Management Account

Viewing insights from the management account is similar to viewing insights from the delegated administrator, so the process listed for the delegated administrator also applies to the management account. Although the management account can view insights across the organization, it should be reserved for running administrative tasks across various AWS services at an organization level.

Important notes

Multi-account insight visibility works at a region level, meaning that you can only view insights across the organization within a single AWS region. You must change the AWS region from the region dropdown menu at the top-right corner of the console to view insights from a different AWS region.

For data security reasons, the delegated administrator can only access insights generated across the organization after the selected member account became the delegated administrator. Insights generated across the organization before the delegated administrator registration will remain inaccessible to the delegated administrator.


The steps detailed above show how you can quickly enable multi-account visibility to monitor application health across your entire organization.

AWS Customers are now using AWS DevOps Guru to monitor and improve application performance, and you too can start monitoring your applications by following the instructions in the product documentation. Head over to the AWS DevOps Guru console to get started today.

About the authors

Ifeanyi Okafor

Ifeanyi Okafor is a Product Manager with AWS. He enjoys building products that solve customer problems at scale.

Haider Naqvi

Haider Naqvi is a Solutions Architect at AWS. He has extensive Software Development and Enterprise Architecture experience. He focuses on enabling customers re:Invent and achieve business outcome with AWS. He is based out of New York.

Nick Ardecky

Nick Ardecky is a Software Engineering working with the AWS DevOps Guru team. Nick enjoys building tools and visualizations that improve products and solve customer problems.

Field Notes: Building Multi-Region and Multi-Account Tools with AWS Organizations

Post Syndicated from Cody Penta original https://aws.amazon.com/blogs/architecture/field-notes-building-multi-region-and-multi-account-tools-with-aws-organizations/

It’s common to start with a single AWS account when you are beginning your cloud journey with AWS. Running operations such as creating, reading, updating, and deleting resources in a single AWS account can be straightforward with AWS application program interfaces (APIs). Because an organization grows, so does their account strategy, often splitting workloads across multiple accounts. Fortunately, AWS customers can use AWS Organizations to group these accounts into logical units, also known as organizational units (OUs), to apply common policies and deploy standard infrastructure. However, this will result in an increased difficulty to run an API against all accounts, moreover, every Region that account could use. How does an organization answer these questions:

  • What is every Amazon FSx backup I own?
  • How can I do an on-demand batch job that will apply to my entire organization?
  • What is every internet access point across my organization?

This blog post shows us how we can use Organizations, AWS Single Sign-On (AWS SSO), AWS CloudFormation StackSets, and various AWS APIs to effectively build multi-account and multi-region tools that can address use cases like the ones above.

Running an AWS API sequentially across hundreds of accounts—potentially, many Regions—could take hours, depending on the API you call. An important aspect we will cover throughout this solution is the importance of concurrency for these types of tools.

Overview of solution

For this solution, we have created a fictional organization called Tavern that is set up with multiple organizational units (OUs), accounts, and Regions, to reflect a real-world scenario.

Figure 1. Organization configuration example

Figure 1. Organization configuration example

We will set up a user with multi-factor authentication (MFA) enabled so we can sign-in and access an admin user in the root account. Using this admin user, we will deploy a stack set across the organization that enables this user to assume limited permissions into each child account.

Next, we will use the Go programming language because of its native concurrency capabilities. More specifically, we will implement the pipeline concurrency pattern to build a multi-account and multi-region tool that will run APIs across our entire AWS footprint.

Additionally, we will add two common edge cases:

  • We block mass API actions to an account in a suspended OU (not pictured) and the root account.
  • We block API actions in disabled regions.

This will show us how to implement robust error handling in equally powerful tooling.


Let us separate the solution into distinct steps:

  • Create an automation user through AWS SSO.
    • This user can optionally be an IAM user or role assumed into by a third-party identity provider (such as, Azure Active Directory). Note the ARN of this identity because that is the key piece of information we will use for crafting a policy document.
  • Deploy a CloudFormation stack set across the organization that enables this user to assume limited access into each account.
    • For this blog post, we will deploy an organization-wide role with `ec2:DescribeRouteTables` permissions. Feel free to expand or change the permission set based on the type of tool you build.
  • Using Go, AWS Command Line Interface (CLI) v2, and AWS SDK for Go v2:
    1. Authenticate using AWS SSO.
    2. List every account in the organization.
    3. Assume permissions into that account.
    4.  Run an API across every Region in that account.
    5. Aggregate results for every Region.
    6. Aggregate results for every account.
    7. Report back the result.

For additional context, review this GitHub repository that contains all code and assets for this blog post.


For this walkthrough, you should have the following prerequisites:

  • Multiple AWS accounts
  • AWS Organizations
  • AWS SSO (optional)
  • AWS SDK for Go v2
  • AWS CLI v2
  • Go programming knowledge (preferred), especially Go’s concurrency model
  • General programming knowledge

Create an automation user in AWS SSO

The first thing we need to do is create an identity to sign into. This can either be an AWS Identity and Access Management (IAM) user, an IAM role integrated with a third-party identity provider, or—in this case—an AWS SSO user.

  1. Log into the AWS SSO user console.
  2. Press Add user button.
  3. Fill in the appropriate information.
Figure 2.AWS SSO create user

Figure 2. AWS SSO create user

  1. Assign the user to the appropriate group. In this case, we will assign this user to AWSControlTowerAdmins.
Figure 3.Assigning SSO user to a group

Figure 3. Assigning SSO user to a group

  1. Verify the user was created. (Optionally: enable MFA).
Figure 4.Verifying User Creation and MFA

Figure 4. Verifying User Creation and MFA

Deploy a stack set across your organization

To effectively run any API across the organization, we need to deploy a common role that our AWS SSO user can assume across every account. We can use AWS CloudFormation StackSets to deploy this role at scale.

  1. Write the IAM role and associated policy document. The following is an example AWS Cloud Development Kit (AWS CDK) code for such a role. Note that orgAccount, roleName, and ssoUser in the below code will have to be replaced with your own values.
    const role = new iam.Role(this, 'TavernAutomationRole', {
      roleName: 'TavernAutomationRole',
      assumedBy: new iam.ArnPrincipal(`arn:aws:sts::${orgAccount}:assumed-role/${roleName}/${ssoUser}`),
    role.addToPolicy(new PolicyStatement({
      actions: ['ec2:DescribeRouteTables'],
      resources: ['*']
  1. Log into the CloudFormation StackSets console.
  2. Press Create StackSet button.
  3. Upload the CloudFormation template containing the common role to be deployed to the organization by the preferred method.
  4. Specify name and optional description.
  5. Add any standard organization tags, and choose Service-managed permissions option.
  6. Choose Deploy to organization, and decide whether to disable or enable automatic deployment and appropriate account removal behavior. For this blog post, we choose to enable automatic deployment and accounts should remove the stack with removed from the target OU.
  7. For Specify regions, choose US East (N.Virginia). Note, because this stack contains only an IAM role, and IAM is a global service, region choice has no effect.
  8. For Maximum concurrent accounts, choose Percent, and enter 100 (this stack is not dependent on order).
  9. For Failure tolerance, choose Number, and enter 5, account deployment failures before a total rollback happens.
  10. For Region Concurrency, choose Sequential.
  11. Review your choices, note the deployment target (should be r-*), and acknowledge that CloudFormation might create IAM resources with custom names.
  12. Press the Submit button to deploy the stack.

Configure AWS SSO for the AWS CLI

To use our organization tools, we must first configure AWS SSO locally. With the AWS CLI v2, we can run:

aws configure sso

To configure credentials:

  1. Run the preceding command in your terminal.
  2. Follow the prompted steps.
    1. Specify your AWS SSO Start URL:
    2. AWS SSO Region:
  1. Authenticate through the pop-up browser window.
  2. Navigate back to the CLI, and choose the root account (this is where our principle for IAM originates).
  3. Specify the default client region.
  4. Specify the default output format.

Note the CLI profile name. Regardless if you choose to go with the autogenerated one or the custom one, we need this profile name for our upcoming code.

Start coding to utilize the AWS SSO shared profile

After AWS SSO is configured, we can start coding the beginning part of our multi-account tool. Our first step is to list every account belonging to our organization.

var (
    stsc    *sts.Client
    orgc    *organizations.Client
    ec2c    *ec2.Client
    regions []string

// init initializes common AWS SDK clients and pulls in all enabled regions
func init() {
    cfg, err := config.LoadDefaultConfig(context.TODO(), config.WithSharedConfigProfile("tavern-automation"))
    if err != nil {
        log.Fatal("ERROR: Unable to resolve credentials for tavern-automation: ", err)

    stsc = sts.NewFromConfig(cfg)
    orgc = organizations.NewFromConfig(cfg)
    ec2c = ec2.NewFromConfig(cfg)

    // NOTE: By default, only describes regions that are enabled in the root org account, not all Regions
    resp, err := ec2c.DescribeRegions(context.TODO(), &ec2.DescribeRegionsInput{})
    if err != nil {
        log.Fatal("ERROR: Unable to describe regions", err)

    for _, region := range resp.Regions {
        regions = append(regions, *region.RegionName)
    fmt.Println("INFO: Listing all enabled regions:")

// main constructs a concurrent pipeline that pushes every account ID down
// the pipeline, where an action is concurrently run on each account and
// results are aggregated into a single json file
func main() {
    var accounts []string

    paginator := organizations.NewListAccountsPaginator(orgc, &organizations.ListAccountsInput{})
    for paginator.HasMorePages() {
        resp, err := paginator.NextPage(context.TODO())
        if err != nil {
            log.Fatal("ERROR: Unable to list accounts in this organization: ", err)

        for _, account := range resp.Accounts {
            accounts = append(accounts, *account.Id)

Implement concurrency into our code

With a slice of every AWS account, it’s time to concurrently run an API across all accounts. We will use some familiar Go concurrency patterns, as well as fan-out and fan-in.

// ... continued in main

    // Begin pipeline by calling gen with a list of every account
    in := gen(accounts...)

    // Fan out and create individual goroutines handling the requested action (getRoute)
    var out []<-chan models.InternetRoute
    for range accounts {
        c := getRoute(in)
        out = append(out, c)

    // Fans in and collect the routing information from all go routines
    var allRoutes []models.InternetRoute
    for n := range merge(out...) {
        allRoutes = append(allRoutes, n)

In the preceding code, we called a gen() function that started construction of our pipeline. Let’s take a deeper look into this function.

// gen primes the pipeline, creating a single separate goroutine
// that will sequentially put a single account id down the channel
// gen returns the channel so that we can plug it in into the next
// stage
func gen(accounts ...string) <-chan string {
    out := make(chan string)
    go func() {
        for _, account := range accounts {
            out <- account
    return out

We see that gen just initializes the pipeline, and then starts pushing account ID’s down the pipeline one by one.

The next two functions are where all the heavy lifting is done. First, let’s investigate `getRoute()`.

// getRoute queries every route table in an account, including every enabled region, for a
// (i.e. default route) to an internet gateway
func getRoute(in <-chan string) <-chan models.InternetRoute {
    out := make(chan models.InternetRoute)
    go func() {
        for account := range in {
            role := fmt.Sprintf("arn:aws:iam::%s:role/TavernAutomationRole", account)
            creds := stscreds.NewAssumeRoleProvider(stsc, role)

            for _, region := range regions {
                localCfg := aws.Config{
                    Region:      region,
                    Credentials: aws.NewCredentialsCache(creds),

                localEc2Client := ec2.NewFromConfig(localCfg)

                paginator := ec2.NewDescribeRouteTablesPaginator(localEc2Client, &ec2.DescribeRouteTablesInput{})
                for paginator.HasMorePages() {
                    resp, err := paginator.NextPage(context.TODO())
                    if err != nil {
                        fmt.Println("WARNING: Unable to retrieve route tables from account: ", account, err)
                        out <- models.InternetRoute{Account: account}

                    for _, routeTable := range resp.RouteTables {
                        for _, r := range routeTable.Routes {
                            if r.GatewayId != nil && strings.Contains(*r.GatewayId, "igw-") {
                                    "Account: ", account,
                                    " Region: ", region,
                                    " DestinationCIDR: ", *r.DestinationCidrBlock,
                                    " GatewayId: ", *r.GatewayId,
                                out <- models.InternetRoute{
                                    Account:         account,
                                    Region:          region,
                                    Vpc:             routeTable.VpcId,
                                    RouteTable:      routeTable.RouteTableId,
                                    DestinationCidr: r.DestinationCidrBlock,
                                    InternetGateway: r.GatewayId,

    return out

A couple of key points to highlight are as follows:

for account := range in

When iterating over a channel, the current goroutine blocks, meaning we wait here until we get an account ID passed to us before continuing. We’ll keep doing this until our upstream closes the channel. In our case, our upstream closes the channel once it pushes every account ID down the channel.

role := fmt.Sprintf("arn:aws:iam::%s:role/TavernAutomationRole", account)
creds := stscreds.NewAssumeRoleProvider(stsc, role)

Here, we can reference our existing role that we deployed to every account and assume into that role with AWS Security Token Service (STS).

for _, region := range regions {

Lastly, when we have credentials into that account, we need to iterate over every region in that account to ensure we are capturing the entire global presence.

These three key areas are how we build organization-level tools. The remaining code is calling the desired API and delivering the result down to the next stage in our pipeline, where we merge all of the results.

// merge takes every go routine and "plugs" it into a common out channel
// then blocks until every input channel closes, signally that all goroutines
// are done in the previous stage
func merge(cs ...<-chan models.InternetRoute) <-chan models.InternetRoute {
    var wg sync.WaitGroup
    out := make(chan models.InternetRoute)

    output := func(c <-chan models.InternetRoute) {
        for n := range c {
            out <- n

    for _, c := range cs {
        go output(c)

    go func() {
    return out

At the end of the main function, we take our in-memory data structures representing our internet entry points and marshal it into a JSON file.

    // ... continued in main

    savedRoutes, err := json.MarshalIndent(allRoutes, "", "\t")
    if err != nil {
        fmt.Println("ERROR: Unable to marshal internet routes to JSON: ", err)
    ioutil.WriteFile("routes.json", savedRoutes, 0644)

With the code in place, we can run the code with `go run main.go` inside of your preferred terminal. The command will generate results like the following:

    // ... routes.json
        "Account": "REDACTED",
        "Region": "eu-north-1",
        "Vpc": "vpc-1efd6c77",
        "RouteTable": "rtb-1038a979",
        "DestinationCidr": "",
        "InternetGateway": "igw-c1b125a8"
        "Account": " REDACTED ",
        "Region": "eu-north-1",
        "Vpc": "vpc-de109db7",
        "RouteTable": "rtb-e042ce89",
        "DestinationCidr": "",
        "InternetGateway": "igw-cbd457a2"
    // ...

Cleaning up

To avoid incurring future charges, delete the following resources:

  • Stack set through the CloudFormation console
  • AWS SSO user (if you created one)


Creating organization tools that answer difficult questions such as, “show me every internet entry point in our organization,” are possible using Organizations APIs and CloudFormation StackSets. We also learned how to use Go’s native concurrency features to build these tools that scale across hundreds of accounts.

Further steps you might explore include:

  • Visiting the Github Repo to capture the full picture.
  • Taking our sequential solution for iterating over Regions and making it concurrent.
  • Exploring the possibility of accepting functions and interfaces in stages to generalize specific pipeline features.

Thanks for taking the time to read, and feel free to leave comments.

Field Notes provides hands-on technical guidance from AWS Solutions Architects, consultants, and technical account managers, based on their experiences in the field solving real-world business problems for customers.

Enable Security Hub PCI DSS standard across your organization and disable specific controls

Post Syndicated from Pablo Pagani original https://aws.amazon.com/blogs/security/enable-security-hub-pci-dss-standard-across-your-organization-and-disable-specific-controls/

At this time, enabling the PCI DSS standard from within AWS Security Hub enables this compliance framework only within the Amazon Web Services (AWS) account you are presently administering.

This blog post showcases a solution that can be used to customize the configuration and deployment of the PCI DSS standard compliance standard using AWS Security Hub across multiple AWS accounts and AWS Regions managed by AWS Organizations. It also demonstrates how to disable specific standards or controls that aren’t required by your organization to meet its compliance requirement. This solution can be used as a baseline for implementation when creating new AWS accounts through the use of AWS CloudFormation StackSets.

Solution overview

Figure 1 that follows shows a sample account setup using the automated solution in this blog post to enable PCI DSS monitoring and reporting across multiple AWS accounts using AWS Organizations. The hierarchy depicted is of one management account used to monitor two member accounts with infrastructure spanning across multiple Regions. Member accounts are configured to send their Security Hub findings to the designated Security Hub management account for centralized compliance management.

Figure 1: Security Hub deployment using AWS Organizations

Figure 1: Security Hub deployment using AWS Organizations


The following prerequisites must be in place in order to enable the PCI DSS standard:

  1. A designated administrator account for Security Hub.
  2. Security Hub enabled in all the desired accounts and Regions.
  3. Access to the management account for the organization. The account must have the required permissions for stack set operations.
  4. Choose which deployment targets (accounts and Regions) you want to enable the PCI DSS standard. Typically, you set this on the accounts where Security Hub is already enabled, or on the accounts where PCI workloads reside.
  5. (Optional) If you find standards or controls that aren’t applicable to your organization, get the Amazon Resource Names (ARNs) of the desired standards or controls to disable.

Solution Resources

The CloudFormation template that you use in the following steps contains:

Solution deployment

To set up this solution for automated deployment, stage the following CloudFormation StackSet template for rollout via the AWS CloudFormation service. The stack set runs across the organization at the root or organizational units (OUs) level of your choice. You can choose which Regions to run this solution against and also to run it each time a new AWS account is created.

To deploy the solution

  1. Open the AWS Management Console.
  2. Download the sh-pci-enabler.yaml template and save it to an Amazon Simple Storage Services (Amazon S3) bucket on the management account. Make a note of the path to use later.
  3. Navigate to CloudFormation service on the management account. Select StackSets from the menu on the left, and then choose Create StackSet.
    Figure 2: CloudFormation – Create StackSet

    Figure 2: CloudFormation – Create StackSet

  4. On the Choose a template page, go to Specify template and select Amazon S3 URL and enter the path to the sh-pci-enabler.yaml template you saved in step 2 above. Choose Next.
    Figure 3: CloudFormation – Choose a template

    Figure 3: CloudFormation – Choose a template

  5. Enter a name and (optional) description for the StackSet. Choose Next.
    Figure 4: CloudFormation – enter StackSet details

    Figure 4: CloudFormation – enter StackSet details

  6. (Optional) On the Configure StackSet options page, go to Tags and add tags to identify and organize your stack set.
    Figure 5: CloudFormation – Configure StackSet options

    Figure 5: CloudFormation – Configure StackSet options

  7. Choose Next.
  8. On the Set deployment options page, select the desired Regions, and then choose Next.

    Figure 6: CloudFormation – Set deployment options

    Figure 6: CloudFormation – Set deployment options

  9. Review the definition and select I acknowledge that AWS CloudFormation might create IAM resources. Choose Submit.
    Figure 7: CloudFormation – Review, acknowledge, and submit

    Figure 7: CloudFormation – Review, acknowledge, and submit

  10. After you choose Submit, you can monitor the creation of the StackSet from the Operations tab to ensure that deployment is successful.
    Figure 8: CloudFormation – Monitor creation of the StackSet

    Figure 8: CloudFormation – Monitor creation of the StackSet

Disable standards that don’t apply to your organization

To disable a standard that isn’t required by your organization, you can use the same template and steps as described above with a few changes as explained below.

To disable standards

  1. Start by opening the SH-PCI-enabler.yaml template and saving a copy under a new name.
  2. In the template, look for sh.batch_enable_standards. Change it to sh.batch_disable_standards.
  3. Locate standardArn=f”arn:aws:securityhub:{region}::standards/pci-dss/v/3.2.1″ and change it to the desired ARN. To find the correct standard ARN, you can use the AWS Command Line Interface (AWS CLI) or AWS CloudShell to run the command aws securityhub describe-standards.
Figure 9: Describe Security Hub standards using CLI

Figure 9: Describe Security Hub standards using CLI

Note: Be sure to keep the f before the quotation marks and replace any Region you might get from the command with the {region} variable. If the CIS standard doesn’t have the Region defined, remove the variable.

Disable controls that don’t apply to your organization

When you enable a standard, all of the controls for that standard are enabled by default. If necessary, you can disable specific controls within an enabled standard.

When you disable a control, the check for the control is no longer performed, no additional findings are generated for that control, and the related AWS Config rules that Security Hub created are removed.

Security Hub is a regional service. When you disable or enable a control, the change is applied in the Region that you specify in the API request. Also, when you disable an entire standard, Security Hub doesn’t track which controls were disabled. If you enable the standard again later, all of the controls in that standard will be enabled.

To disable a list of controls

  1. Open the Security Hub console and select Security standards from the left menu. For each check you want to disable, select Finding JSON and make a note of each StandardsControlArn to add to your list.

    Note: Another option is to use the DescribeStandardsControls API to create a list of StandardsControlArn to be disabled.


    Figure 10: Security Hub console – finding JSON download option

    Figure 10: Security Hub console – finding JSON download option

  2. Download the StackSet SH-disable-controls.yaml template to your computer.
  3. Use a text editor to open the template file.
  4. Locate the list of controls to disable, and edit the template to replace the provided list of StandardsControlArn with your own list of controls to disable, as shown in the following example. Use a comma as the delimiter for each ARN.
    controls=f"arn:aws:securityhub:{region}:{account_id}:control/aws-foundational-security-best-practices/v/1.0.0/ACM.1, arn:aws:securityhub:{region}:{account_id}:control/aws-foundational-security-best-practices/v/1.0.0/APIGateway.1, arn:aws:securityhub:{region}:{account_id}:control/aws-foundational-security-best-practices/v/1.0.0/APIGateway.2"

  5. Save your changes to the template.
  6. Follow the same steps you used to deploy the PCI DSS standard, but use your edited template.

Note: The region and account_id are set as variables, so you decide in which accounts and Regions to disable the controls from the StackSet deployment options (step 8 in Deploy the solution).


The following are issues you might encounter when you deploy this solution:

  1. StackSets deployment errors: Review the troubleshooting guide for CloudFormation StackSets.
  2. Dependencies issues: To modify the status of any standard or control, Security Hub must be enabled first. If it’s not enabled, the operation will fail. Make sure you meet the prerequisites listed earlier in this blog post. Use CloudWatch logs to analyze possible errors from the Lambda function to help identify the cause.
  3. StackSets race condition error: When creating new accounts, the Organizations service enables Security Hub in the account, and invokes the stack sets during account creation. If the stack set runs before the Security Hub service is enabled, the stack set can’t enable the PCI standard. If this happens, you can fix it by adding the Amazon EventBridge rule as shown in SH-EventRule-PCI-enabler.yaml. The EventBridge rule invokes the SHLambdaFunctionEB Lambda function after Security Hub is enabled.


The AWS Security Hub PCI DSS standard is fundamental for any company involved with storing, processing, or transmitting cardholder data. In this post, you learned how to enable or disable a standard or specific controls in all your accounts throughout the organization to proactively monitor your AWS resources. Frequently reviewing failed security checks, prioritizing their remediation, and aiming for a Security Hub score of 100 percent can help improve your security posture.

Further reading

If you have feedback about this post, submit comments in the Comments section below. If you have questions, please start a new thread on the Security Hub forum.

Want more AWS Security how-to content, news, and feature announcements? Follow us on Twitter.


Pablo Pagani

Pablo is the Latam Security Manager for AWS Professional Services based in Buenos Aires, Argentina. He developed his passion for computers while writing his first lines of code in BASIC using a Talent MSX.


Rogerio Kasa

Rogerio is a Senior SRC Consultant based in Sao Paulo, Brazil. He has more than 20 years experience in information security, including 11 years in financial services as a local information security officer. As a security consultant, he helps customers improve their security posture by understanding business goals and creating controls aligned with their risk strategy.

How to restrict IAM roles to access AWS resources from specific geolocations using AWS Client VPN

Post Syndicated from Artem Lovan original https://aws.amazon.com/blogs/security/how-to-restrict-iam-roles-to-access-aws-resources-from-specific-geolocations-using-aws-client-vpn/

You can improve your organization’s security posture by enforcing access to Amazon Web Services (AWS) resources based on IP address and geolocation. For example, users in your organization might bring their own devices, which might require additional security authorization checks and posture assessment in order to comply with corporate security requirements. Enforcing access to AWS resources based on geolocation can help you to automate compliance with corporate security requirements by auditing the connection establishment requests. In this blog post, we walk you through the steps to allow AWS Identity and Access Management (IAM) roles to access AWS resources only from specific geographic locations.

Solution overview

AWS Client VPN is a managed client-based VPN service that enables you to securely access your AWS resources and your on-premises network resources. With Client VPN, you can access your resources from any location using an OpenVPN-based VPN client. A client VPN session terminates at the Client VPN endpoint, which is provisioned in your Amazon Virtual Private Cloud (Amazon VPC) and therefore enables a secure connection to resources running inside your VPC network.

This solution uses Client VPN to implement geolocation authentication rules. When a client VPN connection is established, authentication is implemented at the first point of entry into the AWS Cloud. It’s used to determine if clients are allowed to connect to the Client VPN endpoint. You configure an AWS Lambda function as the client connect handler for your Client VPN endpoint. You can use the handler to run custom logic that authorizes a new connection. When a user initiates a new client VPN connection, the custom logic is the point at which you can determine the geolocation of this user. In order to enforce geolocation authorization rules, you need:

  • AWS WAF to determine the user’s geolocation based on their IP address.
  • A Network address translation (NAT) gateway to be used as the public origin IP address for all requests to your AWS resources.
  • An IAM policy that is attached to the IAM role and validated by AWS when the request origin IP address matches the IP address of the NAT gateway.

One of the key features of AWS WAF is the ability to allow or block web requests based on country of origin. When the client connection handler Lambda function is invoked by your Client VPN endpoint, the Client VPN service invokes the Lambda function on your behalf. The Lambda function receives the device, user, and connection attributes. The user’s public IP address is one of the device attributes that are used to identify the user’s geolocation by using the AWS WAF geolocation feature. Only connections that are authorized by the Lambda function are allowed to connect to the Client VPN endpoint.

Note: The accuracy of the IP address to country lookup database varies by region. Based on recent tests, the overall accuracy for the IP address to country mapping is 99.8 percent. We recommend that you work with regulatory compliance experts to decide if your solution meets your compliance needs.

A NAT gateway allows resources in a private subnet to connect to the internet or other AWS services, but prevents a host on the internet from connecting to those resources. You must also specify an Elastic IP address to associate with the NAT gateway when you create it. Since an Elastic IP address is static, any request originating from a private subnet will be seen with a public IP address that you can trust because it will be the elastic IP address of your NAT gateway.

AWS Identity and Access Management (IAM) is a web service for securely controlling access to AWS services. You manage access in AWS by creating policies and attaching them to IAM identities (users, groups of users, or roles) or AWS resources. A policy is an object in AWS that, when associated with an identity or resource, defines their permissions. In an IAM policy, you can define the global condition key aws:SourceIp to restrict API calls to your AWS resources from specific IP addresses.

Note: Throughout this post, the user is authenticating with a SAML identity provider (IdP) and assumes an IAM role.

Figure 1 illustrates the authentication process when a user tries to establish a new Client VPN connection session.

Figure 1: Enforce connection to Client VPN from specific geolocations

Figure 1: Enforce connection to Client VPN from specific geolocations

Let’s look at how the process illustrated in Figure 1 works.

  1. The user device initiates a new client VPN connection session.
  2. The Client VPN service redirects the user to authenticate against an IdP.
  3. After user authentication succeeds, the client connects to the Client VPN endpoint.
  4. The Client VPN endpoint invokes the Lambda function synchronously. The function is invoked after device and user authentication, and before the authorization rules are evaluated.
  5. The Lambda function extracts the public-ip device attribute from the input and makes an HTTPS request to the Amazon API Gateway endpoint, passing the user’s public IP address in the X-Forwarded-For header.Because you’re using AWS WAF to protect API Gateway, and have geographic match conditions configured, a response with the status code 200 is returned only if the user’s public IP address originates from an allowed country of origin. Additionally, AWS WAF has another rule configured that blocks all requests to API Gateway if the request doesn’t originate from one of the NAT gateway IP addresses. Because Lambda is deployed in a VPC, it has a NAT gateway IP address, and therefore the request isn’t blocked by AWS WAF. To learn more about running a Lambda function in a VPC, see Configuring a Lambda function to access resources in a VPC.The following code example showcases Lambda code that performs the described step.

    Note: Optionally, you can implement additional controls by creating specific authorization rules. Authorization rules act as firewall rules that grant access to networks. You should have an authorization rule for each network for which you want to grant access. To learn more, see Authorization rules.

  6. The Lambda function returns the authorization request response to Client VPN.
  7. When the Lambda function—shown following—returns an allow response, Client VPN establishes the VPN session.
import os
import http.client

cloud_front_url = os.getenv("ENDPOINT_DNS")
endpoint = os.getenv("ENDPOINT")
success_status_codes = [200]

def build_response(allow, status):
    return {
        "allow": allow,
        "error-msg-on-failed-posture-compliance": "Error establishing connection. Please contact your administrator.",
        "posture-compliance-statuses": [status],
        "schema-version": "v1"

def handler(event, context):
    ip = event['public-ip']

    conn = http.client.HTTPSConnection(cloud_front_url)
    conn.request("GET", f'/{endpoint}', headers={'X-Forwarded-For': ip})
    r1 = conn.getresponse()

    status_code = r1.status

    if status_code in success_status_codes:
        print("User's IP is based from an allowed country. Allowing the connection to VPN.")
        return build_response(True, 'compliant')

    print("User's IP is NOT based from an allowed country. Blocking the connection to VPN.")
    return build_response(False, 'quarantined')

After the client VPN session is established successfully, the request from the user device flows through the NAT gateway. The originating source IP address is recognized, because it is the Elastic IP address associated with the NAT gateway. An IAM policy is defined that denies any request to your AWS resources that doesn’t originate from the NAT gateway Elastic IP address. By attaching this IAM policy to users, you can control which AWS resources they can access.

Figure 2 illustrates the process of a user trying to access an Amazon Simple Storage Service (Amazon S3) bucket.

Figure 2: Enforce access to AWS resources from specific IPs

Figure 2: Enforce access to AWS resources from specific IPs

Let’s look at how the process illustrated in Figure 2 works.

  1. A user signs in to the AWS Management Console by authenticating against the IdP and assumes an IAM role.
  2. Using the IAM role, the user makes a request to list Amazon S3 buckets. The IAM policy of the user is evaluated to form an allow or deny decision.
  3. If the request is allowed, an API request is made to Amazon S3.

The aws:SourceIp condition key is used in a policy to deny requests from principals if the origin IP address isn’t the NAT gateway IP address. However, this policy also denies access if an AWS service makes calls on a principal’s behalf. For example, when you use AWS CloudFormation to provision a stack, it provisions resources by using its own IP address, not the IP address of the originating request. In this case, you use aws:SourceIp with the aws:ViaAWSService key to ensure that the source IP address restriction applies only to requests made directly by a principal.

IAM deny policy

The IAM policy doesn’t allow any actions. What the policy does is deny any action on any resource if the source IP address doesn’t match any of the IP addresses in the condition. Use this policy in combination with other policies that allow specific actions.


Make sure that you have the following in place before you deploy the solution:

Implementation and deployment details

In this section, you create a CloudFormation stack that creates AWS resources for this solution. To start the deployment process, select the following Launch Stack button.

Select the Launch Stack button to launch the template

You also can download the CloudFormation template if you want to modify the code before the deployment.

The template in Figure 3 takes several parameters. Let’s go over the key parameters.

Figure 3: CloudFormation stack parameters

Figure 3: CloudFormation stack parameters

The key parameters are:

  • AuthenticationOption: Information about the authentication method to be used to authenticate clients. You can choose either AWS Managed Microsoft AD or IAM SAML identity provider for authentication.
  • AuthenticationOptionResourceIdentifier: The ID of the AWS Managed Microsoft AD directory to use for Active Directory authentication, or the Amazon Resource Number (ARN) of the SAML provider for federated authentication.
  • ServerCertificateArn: The ARN of the server certificate. The server certificate must be provisioned in ACM.
  • CountryCodes: A string of comma-separated country codes. For example: US,GB,DE. The country codes must be alpha-2 country ISO codes of the ISO 3166 international standard.
  • LambdaProvisionedConcurrency: Provisioned concurrency for the client connection handler. We recommend that you configure provisioned concurrency for the Lambda function to enable it to scale without fluctuations in latency.

All other input fields have default values that you can either accept or override. Once you provide the parameter input values and reach the final screen, choose Create stack to deploy the CloudFormation stack.

This template creates several resources in your AWS account, as follows:

  • A VPC and associated resources, such as InternetGateway, Subnets, ElasticIP, NatGateway, RouteTables, and SecurityGroup.
  • A Client VPN endpoint, which provides connectivity to your VPC.
  • A Lambda function, which is invoked by the Client VPN endpoint to determine the country origin of the user’s IP address.
  • An API Gateway for the Lambda function to make an HTTPS request.
  • AWS WAF in front of API Gateway, which only allows requests to go through to API Gateway if the user’s IP address is based in one of the allowed countries.
  • A deny policy with a NAT gateway IP addresses condition. Attaching this policy to a role or user enforces that the user can’t access your AWS resources unless they are connected to your client VPN.

Note: CloudFormation stack deployment can take up to 20 minutes to provision all AWS resources.

After creating the stack, there are two outputs in the Outputs section, as shown in Figure 4.

Figure 4: CloudFormation stack outputs

Figure 4: CloudFormation stack outputs

  • ClientVPNConsoleURL: The URL where you can download the client VPN configuration file.
  • IAMRoleClientVpnDenyIfNotNatIP: The IAM policy to be attached to an IAM role or IAM user to enforce access control.

Attach the IAMRoleClientVpnDenyIfNotNatIP policy to a role

This policy is used to enforce access to your AWS resources based on geolocation. Attach this policy to the role that you are using for testing the solution. You can use the steps in Adding IAM identity permissions to do so.

Configure the AWS client VPN desktop application

When you open the URL that you see in ClientVPNConsoleURL, you see the newly provisioned Client VPN endpoint. Select Download Client Configuration to download the configuration file.

Figure 5: Client VPN endpoint

Figure 5: Client VPN endpoint

Confirm the download request by selecting Download.

Figure 6: Client VPN Endpoint - Download Client Configuration

Figure 6: Client VPN Endpoint – Download Client Configuration

To connect to the Client VPN endpoint, follow the steps in Connect to the VPN. After a successful connection is established, you should see the message Connected. in your AWS Client VPN desktop application.

Figure 7: AWS Client VPN desktop application - established VPN connection

Figure 7: AWS Client VPN desktop application – established VPN connection


If you can’t establish a Client VPN connection, here are some things to try:

  • Confirm that the Client VPN connection has successfully established. It should be in the Connected state. To troubleshoot connection issues, you can follow this guide.
  • If the connection isn’t establishing, make sure that your machine has TCP port 35001 available. This is the port used for receiving the SAML assertion.
  • Validate that the user you’re using for testing is a member of the correct SAML group on your IdP.
  • Confirm that the IdP is sending the right details in the SAML assertion. You can use browser plugins, such as SAML-tracer, to inspect the information received in the SAML assertion.

Test the solution

Now that you’re connected to Client VPN, open the console, sign in to your AWS account, and navigate to the Amazon S3 page. Since you’re connected to the VPN, your origin IP address is one of the NAT gateway IPs, and the request is allowed. You can see your S3 bucket, if any exist.

Figure 8: Amazon S3 service console view - user connected to AWS Client VPN

Figure 8: Amazon S3 service console view – user connected to AWS Client VPN

Now that you’ve verified that you can access your AWS resources, go back to the Client VPN desktop application and disconnect your VPN connection. Once the VPN connection is disconnected, go back to the Amazon S3 page and reload it. This time you should see an error message that you don’t have permission to list buckets, as shown in Figure 9.

Figure 9: Amazon S3 service console view - user is disconnected from AWS Client VPN

Figure 9: Amazon S3 service console view – user is disconnected from AWS Client VPN

Access has been denied because your origin public IP address is no longer one of the NAT gateway IP addresses. As mentioned earlier, since the policy denies any action on any resource without an established VPN connection to the Client VPN endpoint, access to all your AWS resources is denied.

Scale the solution in AWS Organizations

With AWS Organizations, you can centrally manage and govern your environment as you grow and scale your AWS resources. You can use Organizations to apply policies that give your teams the freedom to build with the resources they need, while staying within the boundaries you set. By organizing accounts into organizational units (OUs), which are groups of accounts that serve an application or service, you can apply service control policies (SCPs) to create targeted governance boundaries for your OUs. To learn more about Organizations, see AWS Organizations terminology and concepts.

SCPs help you to ensure that your accounts stay within your organization’s access control guidelines across all your accounts within OUs. In particular, these are the key benefits of using SCPs in your AWS Organizations:

  • You don’t have to create an IAM policy with each new account, but instead create one SCP and apply it to one or more OUs as needed.
  • You don’t have to apply the IAM policy to every IAM user or role, existing or new.
  • This solution can be deployed in a separate account, such as a shared infrastructure account. This helps to decouple infrastructure tooling from business application accounts.

The following figure, Figure 10, illustrates the solution in an Organizations environment.

Figure 10: Use SCPs to enforce policy across many AWS accounts

Figure 10: Use SCPs to enforce policy across many AWS accounts

The Client VPN account is the account the solution is deployed into. This account can also be used for other networking related services. The SCP is created in the Organizations root account and attached to one or more OUs. This allows you to centrally control access to your AWS resources.

Let’s review the new condition that’s added to the IAM policy:

"ArnNotLikeIfExists": {
    "aws:PrincipalARN": [

The aws:PrincipalARN condition key allows your AWS services to communicate to other AWS services even though those won’t have a NAT IP address as the source IP address. For instance, when a Lambda function needs to read a file from your S3 bucket.

Note: Appending policies to existing resources might cause an unintended disruption to your application. Consider testing your policies in a test environment or to non-critical resources before applying them to production resources. You can do that by attaching the SCP to a specific OU or to an individual AWS account.


After you’ve tested the solution, you can clean up all the created AWS resources by deleting the CloudFormation stack.


In this post, we showed you how you can restrict IAM users to access AWS resources from specific geographic locations. You used Client VPN to allow users to establish a client VPN connection from a desktop. You used an AWS client connection handler (as a Lambda function), and API Gateway with AWS WAF to identify the user’s geolocation. NAT gateway IPs served as trusted source IPs, and an IAM policy protects access to your AWS resources. Lastly, you learned how to scale this solution to many AWS accounts with Organizations.

If you have feedback about this post, submit comments in the Comments section below.

Want more AWS Security how-to content, news, and feature announcements? Follow us on Twitter.


Artem Lovan

Artem is a Senior Solutions Architect based in New York. He helps customers architect and optimize applications on AWS. He has been involved in IT at many levels, including infrastructure, networking, security, DevOps, and software development.


Faiyaz Desai

Faiyaz leads a solutions architecture team supporting cloud-native customers in New York. His team guides customers in their modernization journeys through business and technology strategies, architectural best practices, and customer innovation. Faiyaz’s focus areas include unified communication, customer experience, network design, and mobile endpoint security.

How ERGO implemented an event-driven security remediation architecture on AWS

Post Syndicated from Adam Sikora original https://aws.amazon.com/blogs/architecture/how-ergo-implemented-an-event-driven-security-remediation-architecture-on-aws/

ERGO is one of the major insurance groups in Germany and Europe. Within the ERGO Group, ERGO Technology & Services S.A. (ET&S), a part of ET&SM holding, has competencies in digital transformation, know-how in creating and implementing complex IT systems with focus on the quality of solutions and a portfolio aligned with the entire value chain of the insurance market.

Business Challenge and Solution

ERGO has a multi-account AWS environment where each project team subscribes to a set of AWS accounts that conforms to workload requirements and security best practices. As ERGO began its cloud journey, CIS Foundations Benchmark Standard was used as the key indicator for measuring compliance. The report showed significant room for security posture improvements. ERGO was looking for a solution that could enable the management of security events at scale. At the same time, they needed to centralize the event response and remediation in near-real time. The goal was to improve the CIS compliance metric and overall security posture.


ERGO uses AWS Organizations to centrally govern the multi-account AWS environment. Integration of AWS Security Hub with AWS Organizations enables ERGO to designate ERGO’s Security Account as the Security Hub administrator/primary account. Other organization accounts are automatically registered as Security Hub member accounts to send events to the Security Account.

An important aspect of the workflow is to maintain segregation of duties and separation of environments. ERGO uses two separate AWS accounts to implement automatic finding remediation:

  • Security Account – this is the primary account with Security Hub where security alerts (findings) from all the AWS accounts of the project are gathered.
  • Service Account – this is the account that can take action on target project (member) AWS accounts. ERGO uses AWS Lambda functions to run remediation actions through AWS Identity and Access Management (IAM) permissions, VPC resources actions, and more.

Within the Security Account, AWS Security Hub serves as the event aggregation solution that gathers multi-account findings from AWS services such as Amazon GuardDuty. ERGO was able to centralize the security findings. But they still needed to develop a solution that routed the filtered, actionable events to the Service Account. The solution had to automate the response to these events based on ERGO’s security policy. ERGO built this solution with the help of Amazon CloudWatch, AWS Step Functions, and AWS Lambda.

ERGO used the integration of AWS Security Hub with Amazon CloudWatch to send all the security events to CloudWatch. The filtering logic of events was managed at two levels. At the first level, ERGO used CloudWatch Events rules that match event patterns to refine the types of events ERGO wanted to focus on.

The second level of filtering logic was more nuanced and related to the remediation action ERGO wanted to take on a detected event. ERGO chose AWS Step Functions to build a workflow that enabled them to further filter the events, in addition to matching them to the suitable remediation action.

Choosing AWS Step Functions enabled ERGO to orchestrate multiple steps. They could also respond to errors in the overall workflow. For example, one of the issues that ERGO encountered was the sporadic failure of the Archival Lambda function. This was due to the Security Hub API Rate Throttling.

ERGO evaluated several workarounds to deal with this situation. They considered using the automatic retries capability of the AWS SDK to make the API call in the Archival function. However, the built-in mechanism was not sufficient in this case. Another option for dealing with rate limit was to throttle the Archival Lambda functions by applying a low reserved concurrency. Another possibility was to batch the events to be SUPPRESSED and process them as one batch at a time. The benefit was in making a single API call at a time, over several parameters.

After much consideration, ERGO decided to use the “retry on error” mechanism of the Step Function to circumvent this problem. This allowed ERGO to manage the error handling directly in the workflow logic. It wasn’t necessary to change the remediation and archival logic of the Lambda functions. This was a huge advantage. Writing and maintaining error handling logic in each one of the Lambda functions would have been time-intensive and complicated.

Additionally, the remediation actions had to be configured and run from the Service Account. That means the Step Function in the Security Account had to trigger a cross-account resource. ERGO had to find a way to integrate the Remediation Lambda in the Service Account with the state machine of the Security Account. ERGO achieved this integration using a Proxy Lambda in the Security Account.

The Proxy Lambda resides in the Security Account and is initiated by the Step Function. It takes as its argument, the function name and function version to start the Remediation function in the service account.

The Remediation functions in the Service Account have permission to take action on Project accounts. As the next step, the Remediation function is invoked on the impacted accounts. This is filtered by the Step Function, which passes the Account ID to Proxy Lambda, which in turn passes this argument to Remediation Lambda. The Remediation function runs the actions on the Project accounts and returns the output to the Proxy Lambda. This is then passed back to the Step Function.

The role that Lambda assumes using the AssumeRole mechanism, is an Organization Level role. It is deployed on every account and has proper permission to perform the remediation.

ERGO Architecture

Figure 1. Technical Solution implementation

  1. Security Hub service in ERGO Project accounts sends security findings to Administrative Account.
  2. Findings are aggregated and sent to CloudWatch Events for filtering.
  3. CloudWatch rules invoke Step Functions as the target. Step Functions process security events based on the event type and treatment required as per CIS Standards.
  4. For events that need to be suppressed without any dependency on the Project Accounts, the Step Function invokes a Lambda function to archive the findings.
  5. For events that need to be executed on the Project accounts, a Step Function invokes a Proxy Lambda with required parameters.
  6. Proxy Lambda in turn, invokes a cross-account Remediation function in Service Account. This has the permissions to run actions in Project accounts.
  7. Based on the event type, corresponding remediation action is run on the impacted Project Account.
  8. Remediation function passes the execution result back to Proxy Lambda to complete the Security event workflow.

Failed remediations are manually resolved in exceptional conditions.


By implementing this event-driven solution, ERGO was able to increase and maintain automated compliance with CIS AWS Foundation Benchmark Standard to about 95%. The remaining findings were evaluated on case basis, per specific Project requirements. This measurable improvement in ERGO compliance posture was achieved with an end-to-end serverless workflow. This offloaded any on-going platform maintenance efforts from the ERGO cloud security team. Working closely with our AWS account and service teams, ERGO will continue to evaluate and make improvements to our architecture.

Field Notes: Enroll Existing AWS Accounts into AWS Control Tower

Post Syndicated from Kishore Vinjam original https://aws.amazon.com/blogs/architecture/field-notes-enroll-existing-aws-accounts-into-aws-control-tower/

Originally published 21 April 2020 to the Field Notes blog, and updated in August 2020 with new prechecks to the account enrollment script. 

Since the launch of AWS Control Tower, customers have been asking for the ability to deploy AWS Control Tower in their existing AWS Organizations and to extend governance to those accounts in their organization.

We are happy that you can now deploy AWS Control Tower in your existing AWS Organizations. The accounts that you launched before deploying AWS Control Tower, what we refer to as unenrolled accounts, remain outside AWS Control Towers’ governance by default. These accounts must be enrolled in the AWS Control Tower explicitly.

When you enroll an account into AWS Control Tower, it deploys baselines and additional guardrails to enable continuous governance on your existing AWS accounts. However, you must perform proper due diligence before enrolling in an account. Refer to the Things to Consider section below for additional information.

In this blog, I show you how to enroll your existing AWS accounts and accounts within the unregistered OUs in your AWS organization under AWS Control Tower programmatically.


Here’s a quick review of some terms used in this post:

  • The Python script provided in this post. This script interacts with multiple AWS services, to identify, validate, and enroll the existing unmanaged accounts into AWS Control Tower.
  • An unregistered organizational unit (OU) is created through AWS Organizations. AWS Control Tower does not manage this OU.
  • An unenrolled account is an existing AWS account that was created outside of AWS Control Tower. It is not managed by AWS Control Tower.
  • A registered organizational unit (OU) is an OU that was created in the AWS Control Tower service. It is managed by AWS Control Tower.
  • When an OU is registered with AWS Control Tower, it means that specific baselines and guardrails are applied to that OU and all of its accounts.
  • An AWS Account Factory account is an AWS account provisioned using account factory in AWS Control Tower.
  • Amazon Elastic Compute Cloud (Amazon EC2) is a web service that provides secure, resizable compute capacity in the cloud.
  • AWS Service Catalog allows you to centrally manage commonly deployed IT services. In the context of this blog, account factory uses AWS Service Catalog to provision new AWS accounts.
  • AWS Organizations helps you centrally govern your environment as you grow and scale your workloads on AWS.
  • AWS Single Sign-On (SSO) makes it easy to centrally manage access to multiple AWS accounts. It also provides users with single sign-on access to all their assigned accounts from one place.

Things to Consider

Enrolling an existing AWS account into AWS Control Tower involves moving an unenrolled account into a registered OU. The Python script provided in this blog allows you to enroll your existing AWS accounts into AWS Control Tower. However, it doesn’t have much context around what resources are running on these accounts. It assumes that you validated the account services before running this script to enroll the account.

Some guidelines to check before you decide to enroll the accounts into AWS Control Tower.

  1. An AWSControlTowerExecution role must be created in each account. If you are using the script provided in this solution, it creates the role automatically for you.
  2. If you have a default VPC in the account, the enrollment process tries to delete it. If any resources are present in the VPC, the account enrollment fails.
  3. If AWS Config was ever enabled on the account you enroll, a default config recorder and delivery channel were created. Delete the configuration-recorder and delivery channel for the account enrollment to work.
  4. Start with enrolling the dev/staging accounts to get a better understanding of any dependencies or impact of enrolling the accounts in your environment.
  5. Create a new Organizational Unit in AWS Control Tower and do not enable any additional guardrails until you enroll in the accounts. You can then enable guardrails one by one to check the impact of the guardrails in your environment.
  6. As an additional option, you can apply AWS Control Tower’s detective guardrails to an existing AWS account before moving them under Control Tower governance. Instructions to apply the guardrails are discussed in detail in AWS Control Tower Detective Guardrails as an AWS Config Conformance Pack blog.


Before you enroll your existing AWS account in to AWS Control Tower, check the prerequisites from AWS Control Tower documentation.

This Python script provided part of this blog, supports enrolling all accounts with in an unregistered OU in to AWS Control Tower. The script also supports enrolling a single account using both email address or account-id of an unenrolled account. Following are a few additional points to be aware of about this solution.

  • Enable trust access with AWS Organizations for AWS CloudFormation StackSets.
  • The email address associated with the AWS account is used as AWS SSO user name with default First Name Admin and Last Name User.
  • Accounts that are in the root of the AWS Organizations can be enrolled one at a time only.
  • While enrolling an entire OU using this script, the AWSControlTowerExecution role is automatically created on all the accounts on this OU.
  • You can enroll a single account with in an unregistered OU using the script. It checks for AWSControlTowerExecution role on the account. If the role doesn’t exist, the role is created on all accounts within the OU.
  • By default, you are not allowed to enroll an account that is in the root of the organization. You must pass an additional flag to launch a role creation stack set across the organization
  • While enrolling a single account that is in the root of the organization, it prompts for additional flag to launch role creation stack set across the organization.
  • The script uses CloudFormation Stack Set Service-Managed Permissions to create the AWSControlTowerExecution role in the unenrolled accounts.

How it works

The following diagram shows the overview of the solution.

Account enrollment

  1. In your AWS Control Tower environment, access an Amazon EC2 instance running in the master account of the AWS Control Tower home Region.
  2. Get temporary credentials for AWSAdministratorAccess from AWS SSO login screen
  3. Download and execute the enroll_script.py script
  4. The script creates the AWSControlTowerExecution role on the target account using Automatic Deployments for a Stack Set feature.
  5. On successful validation of role and organizational units that are given as input, the script launches a new product in Account Factory.
  6. The enrollment process creates an AWS SSO user using the same email address as the AWS account.

Setting up the environment

It takes up to 30 minutes to enroll each AWS account in to AWS Control Tower. The accounts can be enrolled only one at a time. Depending on number of accounts that you are migrating, you must keep the session open long enough. In this section, you see one way of keeping these long running jobs uninterrupted using Amazon EC2 using the screen tool.

Optionally you may use your own compute environment where the session timeouts can be handled. If you go with your own environment, make sure you have python3, screen and a latest version of boto3 installed.

1. Prepare your compute environment:

  • Log in to your AWS Control Tower with AWSAdministratorAccess role.
  • Switch to the Region where you deployed your AWS Control Tower if needed.
  • If necessary, launch a VPC using the stack here and wait for the stack to COMPLETE.
  • If necessary, launch an Amazon EC2 instance using the stack here. Wait for the stack to COMPLETE.
  • While you are on master account, increase the session time duration for AWS SSO as needed. Default is 1 hour and maximum is 12 hours.

2. Connect to the compute environment (one-way):

  • Go to the EC2 Dashboard, and choose Running Instances.
  • Select the EC2 instance that you just created and choose Connect.
  • In Connect to your instance screen, under Connection method, choose EC2InstanceConnect (browser-based SSH connection) and Connect to open a session.
  • Go to AWS Single Sign-On page in your browser. Click on your master account.
  • Choose command line or programmatic access next to AWSAdministratorAccess.
  • From Option 1 copy the environment variables and paste them in to your EC2 terminal screen in step 5 below.

3. Install required packages and variables. You may skip this step, if you used the stack provided in step-1 to launch a new EC2 instance:

  • Install python3 and boto3 on your EC2 instance. You may have to update boto3, if you use your own environment.
$ sudo yum install python3 -y 
$ sudo pip3 install boto3
$ pip3 show boto3
Name: boto3
Version: 1.12.39
  • Change to home directory and download the enroll_account.py script.
$ cd ~
$ wget https://raw.githubusercontent.com/aws-samples/aws-control-tower-reference-architectures/master/customizations/AccountFactory/EnrollAccount/enroll_account.py
  • Set up your home Region on your EC2 terminal.
export AWS_DEFAULT_REGION=<AWSControlTower-Home-Region>

4. Start a screen session in daemon mode. If your session gets timed out, you can open a new session and attach back to the screen.

$ screen -dmS SAM
$ screen -ls
There is a screen on:
        585.SAM (Detached)
1 Socket in /var/run/screen/S-ssm-user.
$ screen -dr 585.SAM 

5. On the screen terminal, paste the environmental variable that you noted down in step 2.

6. Identify the accounts or the unregistered OUs to migrate and run the Python script provide with below mentioned options.

  • Python script usage:
usage: enroll_account.py -o -u|-e|-i -c 
Enroll existing accounts to AWS Control Tower.

optional arguments:
  -h, --help            show this help message and exit
  -o OU, --ou OU        Target Registered OU
  -u UNOU, --unou UNOU  Origin UnRegistered OU
  -e EMAIL, --email EMAIL
                        AWS account email address to enroll in to AWS Control Tower
  -i AID, --aid AID     AWS account ID to enroll in to AWS Control Tower
  -c, --create_role     Create Roles on Root Level
  • Enroll all the accounts from an unregistered OU to a registered OU
$ python3 enroll_account.py -o MigrateToRegisteredOU -u FromUnregisteredOU 
Creating cross-account role on 222233334444, wait 30 sec: RUNNING 
Executing on AWS Account: 570395911111, [email protected] 
Launching Enroll-Account-vinjak-unmgd3 
Status: UNDER_CHANGE. Waiting for 6.0 min to check back the Status 
Status: UNDER_CHANGE. Waiting for 5.0 min to check back the Status 
. . 
Status: UNDER_CHANGE. Waiting for 1.0 min to check back the Status 
SUCCESS: 111122223333 updated Launching Enroll-Account-vinjakSCchild 
Status: UNDER_CHANGE. Waiting for 6.0 min to check back the Status 
ERROR: 444455556666 
Launching Enroll-Account-Vinjak-Unmgd2 
Status: UNDER_CHANGE. Waiting for 6.0 min to check back the Status 
. . 
Status: UNDER_CHANGE. Waiting for 1.0 min to check back the Status 
SUCCESS: 777788889999 updated
  • Use AWS account ID to enroll a single account that is part of an unregistered OU.
$ python3 enroll_account.py -o MigrateToRegisteredOU -i 111122223333
  • Use AWS account email address to enroll a single account from an unregistered OU.
$ python3 enroll_account.py -o MigrateToRegisteredOU -e [email protected]

You are not allowed by default to enroll an AWS account that is in the root of the organization. The script checks for the AWSControlTowerExecution role in the account. If role doesn’t exist, you are prompted to use -c | --create-role. Using -c flag adds the stack instance to the parent organization root. Which means an AWSControlTowerExecution role is created in all the accounts with in the organization.

Note: Ensure installing AWSControlTowerExecution role in all your accounts in the organization, is acceptable in your organization before using -c flag.

If you are unsure about this, follow the instructions in the documentation and create the AWSControlTowerExecution role manually in each account you want to migrate. Rerun the script.

  • Use AWS account ID to enroll a single account that is in root OU (need -c flag).
$ python3 enroll_account.py -o MigrateToRegisteredOU -i 111122223333 -c
  • Use AWS account email address to enroll a single account that is in root OU (need -c flag).
$ python3 enroll_account.py -o MigrateToRegisteredOU -e [email protected] -c

Cleanup steps

On successful completion of enrolling all the accounts into your AWS Control Tower environment, you could clean up the below resources used for this solution.

If you have used templates provided in this blog to launch VPC and EC2 instance, delete the EC2 CloudFormation stack and then VPC template.


Now you can deploy AWS Control Tower in an existing AWS Organization. In this post, I have shown you how to enroll your existing AWS accounts in your AWS Organization into AWS Control Tower environment. By using the procedure in this post, you can programmatically enroll a single account or all the accounts within an organizational unit into an AWS Control Tower environment.

Now that governance has been extended to these accounts, you can also provision new AWS accounts in just a few clicks and have your accounts conform to your company-wide policies.

Additionally, you can use Customizations for AWS Control Tower to apply custom templates and policies to your accounts. With custom templates, you can deploy new resources or apply additional custom policies to the existing and new accounts. This solution integrates with AWS Control Tower lifecycle events to ensure that resource deployments stay in sync with your landing zone. For example, when a new account is created using the AWS Control Tower account factory, the solution ensures that all resources attached to the account’s OUs are automatically deployed.

Mergers and Acquisitions readiness with the Well-Architected Framework

Post Syndicated from Sushanth Mangalore original https://aws.amazon.com/blogs/architecture/mergers-and-acquisitions-readiness-with-the-well-architected-framework/


Companies looking for an acquisition or a successful exit through a merger, undergo a technical assessment as part of the due diligence process. While being a profitable business by itself can attract interest, running a disciplined IT department within your organization can make the acquisition more valuable. As an entity operating cloud workloads on AWS, you can use the AWS Well-Architected Framework. This will demonstrate that your workloads are architected with industry best practices in mind. The Well-Architected Framework explains the pros and cons of decisions you make while building systems on AWS. It consistently measures architectures against best practices observed in customer workloads across several industries. These workloads have achieved continued success on AWS through architectures that are secure, high-performing, resilient, scalable, and efficient. The Well-Architected Framework evaluates your cloud workloads based on five pillars:

  • Operational Excellence: The ability to support development and run workloads effectively, gain insights into your operations, and continuously improve supporting processes and procedures to deliver business value.
  • Security: The ability to protect data, systems, and assets to take advantage of cloud technologies to improve your security.
  • Reliability: The ability of the workload to perform its intended function correctly and consistently. This includes the ability to operate and test the workload through its complete lifecycle.
  • Performance Efficiency: The ability to use computing resources efficiently to meet system requirements, and to maintain that efficiency as demand changes and technologies evolve.
  • Cost Optimization: The ability to run cost-aware workloads that achieve business outcomes while minimizing costs.

The Well-Architected Framework Value Proposition in Mergers & Acquisitions (M&A)

Continuously assess the pre-M&A state of cloud workloads – The Well-Architected state for a workload must be treated as a moving target. New cloud patterns and best practices emerge every day. The Well-Architected Framework constantly evolves to incorporate them. Your workloads can continuously grow, shrink, become more complex, or simpler. Mergers and acquisitions can be a long, drawn-out process, which can take can take months to complete. Well-Architected reviews are recommended for workloads every 6 months to 1 year, or with every major development milestone. This helps guard against IT inertia and allows emerging best practices to be accounted for in your continuously evolving workload architecture. The technical currency can be maintained throughout the M&A process by continuously assessing your workloads against the Well-Architected Framework. The accompanying AWS Well-Architected Tool (AWS WA Tool) helps you track milestones as you make improvements to and measure your progress.

Well-Architected Continuous Improvement Cycle

Standardize through a common framework – One of the biggest challenges in M&As is the standardization of the Enterprise IT post-merger. The IT departments of organizations can operate differently, and have vastly different IT assets, skill sets, and processes. According to a McKinsey article on the Strategic Value of IT in M&A, more than half the synergies available in a merger are related to IT. If the acquirer is also an AWS customer, this can enable the significant synergies in M&As. The Well-Architected Framework can be a foundation on which the two IT departments can find common ground. Even if the acquirer does not have a cloud-based environment like AWS, inheriting a Well-Architected AWS setup can help the post-merger IT landscape evolve.

Integrate seamlessly through Well-Architected landing zones – AWS Control Tower service or AWS Landing Zone solution are options that can provision Well-Architected multi-account AWS environments. Together with AWS Organizations, this makes the IT integration a lot smoother for the AWS environments across enterprises. AWS accounts can detach from one AWS Organization and attach to another seamlessly. The latter can enroll with an existing Control Tower setup to benefit from the security and governance guardrails. In a Well-Architected landing zone, your management account will not have any workloads. As shown in the following diagram, you may move member accounts from your AWS Organization to your acquirer’s AWS Organization under the right Organizational Unit (OU). You can later decommission your AWS Organization and close your management AWS account.

Sample pre-merger AWS environments

Sample post-merger AWS environment

Benefit from faster migration to AWS – using the Well-Architected Framework, you can achieve faster migration to AWS. Workload risks can be mitigated beforehand by using best practices from AWS before the migration. Post migration, the workloads benefit from AWS offerings that already have many of the Well-Architected best practices built into them. The improvement plans from the Well-Architected tool include the recommended AWS services that can address identified risks. Physical IT assets are heavily depreciated during an acquisition and do not fetch valuations close to their original purchase price. AWS workloads that are Well-Architected should be evaluated by the actual business value they provide. By consolidating your IT needs on AWS, you are also decreasing the overhead of vendor consolidation for the acquirer. This can be challenging when multiple active contracts must transfer hands.

Overcome the innovation barrier – At the onset of an M&A, companies may be focusing too much on keeping the lights on through the process. Businesses that do not move forward may fall behind on continuous innovation. Not only can innovation open more business opportunities, but it can also influence the acquisition valuation. Well-Architected reviews can optimize costs. This can result in diverse benefits such as better agility and an increased use of advanced technologies. This can facilitate rapid innovation. Improvements gained in the security posture, reliability, and performance of the workload make it more valuable to the acquirer.

Demonstrate depth in your area of expertise – Well-Architected lenses help evaluate workloads for specific technology or business domains. Lenses dive deeper into the domain-specific best practices for the workload. If your business specializes in a domain for which a Well-Architected lens is available, doing a review with the specific lens will provide more value for your workload. Today, AWS has lenses for serverless, SaaS, High Performance Computing (HPC), the financial services industry, machine learning, IoT workloads and more. We recently announced a new Management and Governance Lens.

Build workloads using AWS vetted constructs – AWS Solutions Library provides you a repository of Well-Architected solutions across a range of technologies and industry verticals. The library includes reference architectures, implementations of reusable patterns, and fully baked end-to-end solution implementations. Use these building blocks to assemble your workloads. Include the AWS recommended best practices into them, and create an attractive proposition to an acquirer.


You can start taking advantage of the Well-Architected Framework today to improve your technical readiness for an acquisition. The Well-Architected Tool in the AWS Management Console allows you to review your workload at no cost. Engage with your AWS account team early, and we can provide the right guidance for your specific M&A, and plan your Well-Architected technical readiness. Using the Well-Architected Framework as the cornerstone, the AWS Solutions Architects and APN partners have guided thousands of customers through this journey. We are looking forward to helping you succeed.