Tag Archives: xml

Security updates for Monday

Post Syndicated from ris original https://lwn.net/Articles/739648/rss

Security updates have been issued by Arch Linux (icu and lib32-icu), CentOS (firefox), Debian (imagemagick, konversation, libspring-ldap-java, libxml-libxml-perl, lynx-cur, ming, opensaml2, poppler, procmail, shibboleth-sp2, and xen), Fedora (firefox, java-9-openjdk, jbig2dec, kernel, knot, knot-resolver, qt5-qtwebengine, and roundcubemail), Gentoo (adobe-flash, couchdb, icedtea-bin, and phpunit), Mageia (apr, bluez, firefox, jq, konversation, libextractor, and quagga), Oracle (firefox), Red Hat (firefox), and Scientific Linux (firefox).

Security updates for Friday

Post Syndicated from jake original https://lwn.net/Articles/738718/rss

Security updates have been issued by Arch Linux (lib32-openssl, libextractor, postgresql, and postgresql-old-upgrade), Debian (bchunk, postgresql-9.4, postgresql-9.6, postgresql-common, roundcube, and tomcat7), Gentoo (libxml2), SUSE (kvm, openssl1, and qemu), and Ubuntu (postgresql-common).

WPSeku – Black-Box Remote WordPress Security Scanner

Post Syndicated from Darknet original https://www.darknet.org.uk/2017/11/wpseku-black-box-remote-wordpress-security-scanner/?utm_source=rss&utm_medium=social&utm_campaign=darknetfeed

WPSeku – Black-Box Remote WordPress Security Scanner

WPSeku is a black box WordPress Security scanner that can be used to scan remote WordPress installations to find security issues and vulnerabilities.

Features of WPSeku WordPress Security Scanner

WPSeku supports various types of scanning including:

  • Testing for XSS Vulnerabilities
  • Testing for SQL Injection Vulnerabilities
  • Testing for LFI Vulnerabilities
  • Bruteforce login via xmlrpc
  • Username Enumeration
  • Proxy Support
  • Method (GET/POST)
  • Custom Wordlists
  • Custom user-agent

It also uses the WPVulnDB Vulnerability Database API at https://wpvulndb.com/api.

Read the rest of WPSeku – Black-Box Remote WordPress Security Scanner now! Only available at Darknet.

XXE Injection Attacks – XML External Entity Vulnerability With Examples

Post Syndicated from Darknet original https://www.darknet.org.uk/2017/10/xxe-injection-attacks-xml-external-entity-vulnerability-examples/?utm_source=rss&utm_medium=social&utm_campaign=darknetfeed

XXE Injection Attacks – XML External Entity Vulnerability With Examples

XXE Injection Attacks or XML External Entity vulnerabilities are a specific type of Server Side Request Forgery or SSRF attack relating to abusing features within XML parsers.

The features these attacks go after are widely available but rarely used and when trigged can cause a DoS (Denial of Service) attack and in some cases much more serious escalation like extraction of sensitive data or in worst case scenarios RCE or Remote Code Execution.

Read the rest of XXE Injection Attacks – XML External Entity Vulnerability With Examples now! Only available at Darknet.

Security updates for Wednesday

Post Syndicated from ris original https://lwn.net/Articles/736063/rss

Security updates have been issued by Arch Linux (lame, salt, and xorg-server), Debian (ffmpeg, imagemagick, libxfont, wordpress, and xen), Fedora (ImageMagick, rubygem-rmagick, and tor), Oracle (kernel), SUSE (kernel, SLES 12 Docker image, SLES 12-SP1 Docker image, and SLES 12-SP2 Docker image), and Ubuntu (curl, glance, horizon, kernel, keystone, libxfont, libxfont1, libxfont2, libxml2, linux, linux-aws, linux-gke, linux-kvm, linux-raspi2, linux-snapdragon, linux, linux-raspi2, linux-gcp, linux-hwe, linux-lts-xenial, nova, openvswitch, swift, and thunderbird).

Backing Up WordPress

Post Syndicated from Roderick Bauer original https://www.backblaze.com/blog/backing-up-wordpress/

WordPress cloud backup
WordPress logo

WordPress is the most popular CMS (Content Management System) for websites, with almost 30% of all websites in the world using WordPress. That’s a lot of sites — over 350 million!

In this post we’ll talk about the different approaches to keeping the data on your WordPress website safe.


Stop the Presses! (Or the Internet!)

As we were getting ready to publish this post, we received news from UpdraftPlus, one of the biggest WordPress plugin developers, that they are supporting Backblaze B2 as a storage solution for their backup plugin. They shipped the update (1.13.9) this week. This is great news for Backblaze customers! UpdraftPlus is also offering a 20% discount to Backblaze customers wishing to purchase or upgrade to UpdraftPlus Premium. The complete information is below.

UpdraftPlus joins backup plugin developer XCloner — Backup and Restore in supporting Backblaze B2. A third developer, BlogVault, also announced their intent to support Backblaze B2. Contact your favorite WordPress backup plugin developer and urge them to support Backblaze B2, as well.

Now, back to our post…


Your WordPress website data is on a web server that’s most likely located in a large data center. You might wonder why it is necessary to have a backup of your website if it’s in a data center. Website data can be lost in a number of ways, including mistakes by the website owner (been there), hacking, or even domain ownership dispute (I’ve seen it happen more than once). A website backup also can provide a history of changes you’ve made to the website, which can be useful. As an overall strategy, it’s best to have a backup of any data that you can’t afford to lose for personal or business reasons.

Your web hosting company might provide backup services as part of your hosting plan. If you are using their service, you should know where and how often your data is being backed up. You don’t want to find out too late that your backup plan was not adequate.

Sites on WordPress.com are automatically backed up by VaultPress (Automattic), which also is available for self-hosted WordPress installations. If you don’t want the work or decisions involved in managing the hosting for your WordPress site, WordPress.com will handle it for you. You do, however, give up some customization abilities, such as the option to add plugins of your own choice.

Very large and active websites might consider WordPress VIP by Automattic, or another premium WordPress hosting service such as Pagely.com.

This post is about backing up self-hosted WordPress sites, so we’ll focus on those options.

WordPress Backup

Backup strategies for WordPress can be divided into broad categories depending on 1) what you back up, 2) when you back up, and 3) where the data is backed up.

With server data, such as with a WordPress installation, you should plan to have three copies of the data (the 3-2-1 backup strategy). The first is the active data on the WordPress web server, the second is a backup stored on the web server or downloaded to your local computer, and the third should be in another location, such as the cloud.

We’ll talk about the different approaches to backing up WordPress, but we recommend using a WordPress plugin to handle your backups. A backup plugin can automate the task, optimize your backup storage space, and alert you of problems with your backups or WordPress itself. We’ll cover plugins in more detail, below.

What to Back Up?

The main components of your WordPress installation are:

You should decide which of these elements you wish to back up. The database is the top priority, as it contains all your website posts and pages (exclusive of media). Your current theme is important, as it likely contains customizations you’ve made. Following those in priority are any other files you’ve customized or made changes to.

You can choose to back up the WordPress core installation and plugins, if you wish, but these files can be downloaded again if necessary from the source, so you might not wish to include them. You likely have all the media files you use on your website on your local computer (which should be backed up), so it is your choice whether to back these up from the server as well.

If you wish to be able to recreate your entire website easily in case of data loss or disaster, you might choose to back up everything, though on a large website this could be a lot of data.

Generally, you should 1) prioritize any file that you’ve customized that you can’t afford to lose, and 2) decide whether you need a copy of everything in order to get your site back up quickly. These choices will determine your backup method and the amount of storage you need.

A good backup plugin for WordPress enables you to specify which files you wish to back up, and even to create separate backups and schedules for different backup contents. That’s another good reason to use a plugin for backing up WordPress.

When to Back Up?

You can back up manually at any time by using the Export tool in WordPress. This is handy if you wish to do a quick backup of your site or parts of it. Since it is manual, however, it is not a part of a dependable backup plan that should be done regularly. If you wish to use this tool, go to Tools, Export, and select what you wish to back up. The output will be an XML file that uses the WordPress Extended RSS format, also known as WXR. You can create a WXR file that contains all of the information on your site or just portions of the site, such as posts or pages by selecting: All content, Posts, Pages, or Media.
Note: You can use WordPress’s Export tool for sites hosted on WordPress.com, as well.

Export instruction for WordPress

Many of the backup plugins we’ll be discussing later also let you do a manual backup on demand in addition to regularly scheduled or continuous backups.

Note:  Another use of the WordPress Export tool and the WXR file is to transfer or clone your website to another server. Once you have exported the WXR file from the website you wish to transfer from, you can import the WXR file from the Tools, Import menu on the new WordPress destination site. Be aware that there are file size limits depending on the settings on your web server. See the WordPress Codex entry for more information. To make this job easier, you may wish to use one of a number of WordPress plugins designed specifically for this task.

You also can manually back up the WordPress MySQL database using a number of tools or a plugin. The WordPress Codex has good information on this. All WordPress plugins will handle this for you and do it automatically. They also typically include tools for optimizing the database tables, which is just good housekeeping.

A dependable backup strategy doesn’t rely on manual backups, which means you should consider using one of the many backup plugins available either free or for purchase. We’ll talk more about them below.

Which Format To Back Up In?

In addition to the WordPress WXR format, plugins and server tools will use various file formats and compression algorithms to store and compress your backup. You may get to choose between zip, tar, tar.gz, tar.gz2, and others. See The Most Common Archive File Formats for more information on these formats.

Select a format that you know you can access and unarchive should you need access to your backup. All of these formats are standard and supported across operating systems, though you might need to download a utility to access the file.

Where To Back Up?

Once you have your data in a suitable format for backup, where do you back it up to?

We want to have multiple copies of our active website data, so we’ll choose more than one destination for our backup data. The backup plugins we’ll discuss below enable you to specify one or more possible destinations for your backup. The possible destinations for your backup include:

A backup folder on your web server
A backup folder on your web server is an OK solution if you also have a copy elsewhere. Depending on your hosting plan, the size of your site, and what you include in the backup, you may or may not have sufficient disk space on the web server. Some backup plugins allow you to configure the plugin to keep only a certain number of recent backups and delete older ones, saving you disk space on the server.
Email to you
Because email servers have size limitations, the email option is not the best one to use unless you use it to specifically back up just the database or your main theme files.
FTP, SFTP, SCP, WebDAV
FTP, SFTP, SCP, and WebDAV are all widely-supported protocols for transferring files over the internet and can be used if you have access credentials to another server or supported storage device that is suitable for storing a backup.
Sync service (Dropbox, SugarSync, Google Drive, OneDrive)
A sync service is another possible server storage location though it can be a pricier choice depending on the plan you have and how much you wish to store.
Cloud storage (Backblaze B2, Amazon S3, Google Cloud, Microsoft Azure, Rackspace)
A cloud storage service can be an inexpensive and flexible option with pay-as-you go pricing for storing backups and other data.

A good website backup strategy would be to have multiple backups of your website data: one in a backup folder on your web hosting server, one downloaded to your local computer, and one in the cloud, such as with Backblaze B2.

If I had to choose just one of these, I would choose backing up to the cloud because it is geographically separated from both your local computer and your web host, it uses fault-tolerant and redundant data storage technologies to protect your data, and it is available from anywhere if you need to restore your site.

Backup Plugins for WordPress

Probably the easiest and most common way to implement a solid backup strategy for WordPress is to use one of the many backup plugins available for WordPress. Fortunately, there are a number of good ones and are available free or in “freemium” plans in which you can use the free version and pay for more features and capabilities only if you need them. The premium options can give you more flexibility in configuring backups or have additional options for where you can store the backups.

How to Choose a WordPress Backup Plugin

screenshot of WordPress plugins search

When considering which plugin to use, you should take into account a number of factors in making your choice.

Is the plugin actively maintained and up-to-date? You can determine this from the listing in the WordPress Plugin Repository. You also can look at reviews and support comments to get an idea of user satisfaction and how well issues are resolved.

Does the plugin work with your web hosting provider? Generally, well-supported plugins do, but you might want to check to make sure there are no issues with your hosting provider.

Does it support the cloud service or protocol you wish to use? This can be determined from looking at the listing in the WordPress Plugin Repository or on the developer’s website. Developers often will add support for cloud services or other backup destinations based on user demand, so let the developer know if there is a feature or backup destination you’d like them to add to their plugin.

Other features and options to consider in choosing a backup plugin are:

  • Whether encryption of your backup data is available
  • What are the options for automatically deleting backups from the storage destination?
  • Can you globally exclude files, folders, and specific types of files from the backup?
  • Do the options for scheduling automatic backups meet your needs for frequency?
  • Can you exclude/include specific database tables (a good way to save space in your backup)?

WordPress Backup Plugins Review

Let’s review a few of the top choices for WordPress backup plugins.

UpdraftPlus

UpdraftPlus is one of the most popular backup plugins for WordPress with over one million active installations. It is available in both free and Premium versions.

UpdraftPlus just released support for Backblaze B2 Cloud Storage in their 1.13.9 update on September 25. According to the developer, support for Backblaze B2 was the most frequent request for a new storage option for their plugin. B2 support is available in their Premium plugin and as a stand-alone update to their standard product.

Note: The developers of UpdraftPlus are offering a special 20% discount to Backblaze customers on the purchase of UpdraftPlus Premium by using the coupon code backblaze20. The discount is valid until the end of Friday, October 6th, 2017.

screenshot of Backblaze B2 cloud backup for WordPress in UpdraftPlus

XCloner — Backup and Restore

XCloner — Backup and Restore is a useful open-source plugin with many options for backing up WordPress.

XCloner supports B2 Cloud Storage in their free plugin.

screenshot of XCloner WordPress Backblaze B2 backup settings

BlogVault

BlogVault describes themselves as a “complete WordPress backup solution.” They offer a free trial of their paid WordPress backup subscription service that features real-time backups of changes to your WordPress site, as well as many other features.

BlogVault has announced their intent to support Backblaze B2 Cloud Storage in a future update.

screenshot of BlogValut WordPress Backup settings

BackWPup

BackWPup is a popular and free option for backing up WordPress. It supports a number of options for storing your backup, including the cloud, FTP, email, or on your local computer.

screenshot of BackWPup WordPress backup settings

WPBackItUp

WPBackItUp has been around since 2012 and is highly rated. It has both free and paid versions.

screenshot of WPBackItUp WordPress backup settings

VaultPress

VaultPress is part of Automattic’s well-known WordPress product, JetPack. You will need a JetPack subscription plan to use VaultPress. There are different pricing plans with different sets of features.

screenshot of VaultPress backup settings

Backup by Supsystic

Backup by Supsystic supports a number of options for backup destinations, encryption, and scheduling.

screenshot of Backup by Supsystic backup settings

BackupWordPress

BackUpWordPress is an open-source project on Github that has a popular and active following and many positive reviews.

screenshot of BackupWordPress WordPress backup settings

BackupBuddy

BackupBuddy, from iThemes, is the old-timer of backup plugins, having been around since 2010. iThemes knows a lot about WordPress, as they develop plugins, themes, utilities, and provide training in WordPress.

BackupBuddy’s backup includes all WordPress files, all files in the WordPress Media library, WordPress themes, and plugins. BackupBuddy generates a downloadable zip file of the entire WordPress website. Remote storage destinations also are supported.

screenshot of BackupBuddy settings

WordPress and the Cloud

Do you use WordPress and back up to the cloud? We’d like to hear about it. We’d also like to hear whether you are interested in using B2 Cloud Storage for storing media files served by WordPress. If you are, we’ll write about it in a future post.

In the meantime, keep your eye out for new plugins supporting Backblaze B2, or better yet, urge them to support B2 if they’re not already.

The Best Backup Strategy is the One You Use

There are other approaches and tools for backing up WordPress that you might use. If you have an approach that works for you, we’d love to hear about it in the comments.

The post Backing Up WordPress appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

Security updates for Monday

Post Syndicated from ris original https://lwn.net/Articles/734761/rss

Security updates have been issued by Debian (bzr, clamav, libgd2, libraw, samba, and tomcat7), Fedora (drupal7-views, gnome-shell, httpd, krb5, libmspack, LibRaw, mingw-LibRaw, mpg123, pkgconf, python-jwt, and samba), Gentoo (adobe-flash, chromium, cvs, exim, mercurial, oracle-jdk-bin, php, postfix, and tcpdump), openSUSE (Chromium and libraw), Red Hat (chromium-browser), and Slackware (libxml2 and python).

Security updates for Tuesday

Post Syndicated from ris original https://lwn.net/Articles/734142/rss

Security updates have been issued by Arch Linux (apache and ettercap), Debian (gdk-pixbuf and newsbeuter), Red Hat (kernel), Slackware (httpd, libgcrypt, and ruby), SUSE (kernel), and Ubuntu (bind9, kernel, libidn2-0, libxml2, linux, linux-aws, linux-gke, linux-kvm, linux-raspi2, linux-snapdragon, linux, linux-raspi2, linux-hwe, linux-lts-trusty, and linux-lts-xenial).

Security updates for Tuesday

Post Syndicated from corbet original https://lwn.net/Articles/731678/rss

Security updates have been issued by Debian (extplorer and libraw), Fedora (mingw-libsoup, python-tablib, ruby, and subversion), Mageia (avidemux, clamav, nasm, php-pear-CAS, and shutter), Oracle (xmlsec1), Red Hat (openssl tomcat), Scientific Linux (authconfig, bash, curl, evince, firefox, freeradius, gdm gnome-session, ghostscript, git, glibc, gnutls, groovy, GStreamer, gtk-vnc, httpd, java-1.7.0-openjdk, kernel, libreoffice, libsoup, libtasn1, log4j, mariadb, mercurial, NetworkManager, openldap, openssh, pidgin, pki-core, postgresql, python, qemu-kvm, samba, spice, subversion, tcpdump, tigervnc fltk, tomcat, X.org, and xmlsec1), SUSE (git), and Ubuntu (augeas, cvs, and texlive-base).

Security updates for Monday

Post Syndicated from jake original https://lwn.net/Articles/731567/rss

Security updates have been issued by Arch Linux (newsbeuter), Debian (augeas, curl, ioquake3, libxml2, newsbeuter, and strongswan), Fedora (bodhi, chicken, chromium, cryptlib, cups-filters, cyrus-imapd, glibc, mingw-openjpeg2, mingw-postgresql, qpdf, and torbrowser-launcher), Gentoo (bzip2, evilvte, ghostscript-gpl, Ked Password Manager, and rar), Mageia (curl, cvs, fossil, jetty, kernel, kernel-linus, kernel-tmb, libmspack, mariadb, mercurial, potrace, ruby, and taglib), Oracle (kernel), Red Hat (xmlsec1), and Ubuntu (graphite2 and strongswan).

Security updates for Thursday

Post Syndicated from jake original https://lwn.net/Articles/731309/rss

Security updates have been issued by CentOS (git), Debian (firefox-esr and mariadb-10.0), Gentoo (bind and tnef), Mageia (kauth, kdelibs4, poppler, subversion, and vim), openSUSE (fossil, git, libheimdal, libxml2, minicom, nodejs4, nodejs6, openjpeg2, openldap2, potrace, subversion, and taglib), Oracle (git and kernel), Red Hat (git, groovy, httpd24-httpd, and mercurial), Scientific Linux (git), and SUSE (freeradius-server, ImageMagick, and subversion).

Wanted: Front End Developer

Post Syndicated from Yev original https://www.backblaze.com/blog/wanted-front-end-developer/

Want to work at a company that helps customers in over 150 countries around the world protect the memories they hold dear? Do you want to challenge yourself with a business that serves consumers, SMBs, Enterprise, and developers? If all that sounds interesting, you might be interested to know that Backblaze is looking for a Front End Developer​!

Backblaze is a 10 year old company. Providing great customer experiences is the “secret sauce” that enables us to successfully compete against some of technology’s giants. We’ll finish the year at ~$20MM ARR and are a profitable business. This is an opportunity to have your work shine at scale in one of the fastest growing verticals in tech – Cloud Storage.

You will utilize HTML, ReactJS, CSS and jQuery to develop intuitive, elegant user experiences. As a member of our Front End Dev team, you will work closely with our web development, software design, and marketing teams.

On a day to day basis, you must be able to convert image mockups to HTML or ReactJS – There’s some production work that needs to get done. But you will also be responsible for helping build out new features, rethink old processes, and enabling third party systems to empower our marketing/sales/ and support teams.

Our Front End Developer must be proficient in:

  • HTML, ReactJS
  • UTF-8, Java Properties, and Localized HTML (Backblaze runs in 11 languages!)
  • JavaScript, CSS, Ajax
  • jQuery, Bootstrap
  • JSON, XML
  • Understanding of cross-browser compatibility issues and ways to work around them
  • Basic SEO principles and ensuring that applications will adhere to them
  • Learning about third party marketing and sales tools through reading documentation. Our systems include Google Tag Manager, Google Analytics, Salesforce, and Hubspot

Struts, Java, JSP, Servlet and Apache Tomcat are a plus, but not required.

We’re looking for someone that is:

  • Passionate about building friendly, easy to use Interfaces and APIs.
  • Likes to work closely with other engineers, support, and marketing to help customers.
  • Is comfortable working independently on a mutually agreed upon prioritization queue (we don’t micromanage, we do make sure tasks are reasonably defined and scoped).
  • Diligent with quality control. Backblaze prides itself on giving our team autonomy to get work done, do the right thing for our customers, and keep a pace that is sustainable over the long run. As such, we expect everyone that checks in code that is stable. We also have a small QA team that operates as a secondary check when needed.

Backblaze Employees Have:

  • Good attitude and willingness to do whatever it takes to get the job done
  • Strong desire to work for a small fast, paced company
  • Desire to learn and adapt to rapidly changing technologies and work environment
  • Comfort with well behaved pets in the office

This position is located in San Mateo, California. Regular attendance in the office is expected. Backblaze is an Equal Opportunity Employer and we offer competitive salary and benefits, including our no policy vacation policy.

If this sounds like you
Send an email to [email protected] with:

  1. Front End Dev​ in the subject line
  2. Your resume attached
  3. An overview of your relevant experience

The post Wanted: Front End Developer appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

Security updates for Friday

Post Syndicated from ris original https://lwn.net/Articles/730629/rss

Security updates have been issued by Arch Linux (firefox, flashplugin, lib32-flashplugin, libsoup, and varnish), Debian (freeradius, git, libsoup2.4, pjproject, postgresql-9.1, postgresql-9.4, postgresql-9.6, subversion, and xchat), Fedora (gsoap, irssi, knot-resolver, php-horde-horde, php-horde-Horde-Core, php-horde-Horde-Form, php-horde-Horde-Url, php-horde-kronolith, php-horde-nag, and php-horde-turba), Mageia (perl-XML-LibXML), Oracle (libsoup), Red Hat (firefox and libsoup), SUSE (kernel and libsoup), and Ubuntu (git, kernel, libsoup2.4, linux, linux-aws, linux-gke, linux-raspi2, linux-snapdragon, linux, linux-raspi2, linux-hwe, linux-lts-trusty, linux-lts-xenial, php5, php7.0, and subversion).

Deploying an NGINX Reverse Proxy Sidecar Container on Amazon ECS

Post Syndicated from Nathan Peck original https://aws.amazon.com/blogs/compute/nginx-reverse-proxy-sidecar-container-on-amazon-ecs/

Reverse proxies are a powerful software architecture primitive for fetching resources from a server on behalf of a client. They serve a number of purposes, from protecting servers from unwanted traffic to offloading some of the heavy lifting of HTTP traffic processing.

This post explains the benefits of a reverse proxy, and explains how to use NGINX and Amazon EC2 Container Service (Amazon ECS) to easily implement and deploy a reverse proxy for your containerized application.

Components

NGINX is a high performance HTTP server that has achieved significant adoption because of its asynchronous event driven architecture. It can serve thousands of concurrent requests with a low memory footprint. This efficiency also makes it ideal as a reverse proxy.

Amazon ECS is a highly scalable, high performance container management service that supports Docker containers. It allows you to run applications easily on a managed cluster of Amazon EC2 instances. Amazon ECS helps you get your application components running on instances according to a specified configuration. It also helps scale out these components across an entire fleet of instances.

Sidecar containers are a common software pattern that has been embraced by engineering organizations. It’s a way to keep server side architecture easier to understand by building with smaller, modular containers that each serve a simple purpose. Just like an application can be powered by multiple microservices, each microservice can also be powered by multiple containers that work together. A sidecar container is simply a way to move part of the core responsibility of a service out into a containerized module that is deployed alongside a core application container.

The following diagram shows how an NGINX reverse proxy sidecar container operates alongside an application server container:

In this architecture, Amazon ECS has deployed two copies of an application stack that is made up of an NGINX reverse proxy side container and an application container. Web traffic from the public goes to an Application Load Balancer, which then distributes the traffic to one of the NGINX reverse proxy sidecars. The NGINX reverse proxy then forwards the request to the application server and returns its response to the client via the load balancer.

Reverse proxy for security

Security is one reason for using a reverse proxy in front of an application container. Any web server that serves resources to the public can expect to receive lots of unwanted traffic every day. Some of this traffic is relatively benign scans by researchers and tools, such as Shodan or nmap:

[18/May/2017:15:10:10 +0000] "GET /YesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScanningForResearchPurposePleaseHaveALookAtTheUserAgentTHXYesThisIsAReallyLongRequestURLbutWeAreDoingItOnPurposeWeAreScann HTTP/1.1" 404 1389 - Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.86 Safari/537.36
[18/May/2017:18:19:51 +0000] "GET /clientaccesspolicy.xml HTTP/1.1" 404 322 - Cloud mapping experiment. Contact [email protected]

But other traffic is much more malicious. For example, here is what a web server sees while being scanned by the hacking tool ZmEu, which scans web servers trying to find PHPMyAdmin installations to exploit:

[18/May/2017:16:27:39 +0000] "GET /mysqladmin/scripts/setup.php HTTP/1.1" 404 391 - ZmEu
[18/May/2017:16:27:39 +0000] "GET /web/phpMyAdmin/scripts/setup.php HTTP/1.1" 404 394 - ZmEu
[18/May/2017:16:27:39 +0000] "GET /xampp/phpmyadmin/scripts/setup.php HTTP/1.1" 404 396 - ZmEu
[18/May/2017:16:27:40 +0000] "GET /apache-default/phpmyadmin/scripts/setup.php HTTP/1.1" 404 405 - ZmEu
[18/May/2017:16:27:40 +0000] "GET /phpMyAdmin-2.10.0.0/scripts/setup.php HTTP/1.1" 404 397 - ZmEu
[18/May/2017:16:27:40 +0000] "GET /mysql/scripts/setup.php HTTP/1.1" 404 386 - ZmEu
[18/May/2017:16:27:41 +0000] "GET /admin/scripts/setup.php HTTP/1.1" 404 386 - ZmEu
[18/May/2017:16:27:41 +0000] "GET /forum/phpmyadmin/scripts/setup.php HTTP/1.1" 404 396 - ZmEu
[18/May/2017:16:27:41 +0000] "GET /typo3/phpmyadmin/scripts/setup.php HTTP/1.1" 404 396 - ZmEu
[18/May/2017:16:27:42 +0000] "GET /phpMyAdmin-2.10.0.1/scripts/setup.php HTTP/1.1" 404 399 - ZmEu
[18/May/2017:16:27:44 +0000] "GET /administrator/components/com_joommyadmin/phpmyadmin/scripts/setup.php HTTP/1.1" 404 418 - ZmEu
[18/May/2017:18:34:45 +0000] "GET /phpmyadmin/scripts/setup.php HTTP/1.1" 404 390 - ZmEu
[18/May/2017:16:27:45 +0000] "GET /w00tw00t.at.blackhats.romanian.anti-sec:) HTTP/1.1" 404 401 - ZmEu

In addition, servers can also end up receiving unwanted web traffic that is intended for another server. In a cloud environment, an application may end up reusing an IP address that was formerly connected to another service. It’s common for misconfigured or misbehaving DNS servers to send traffic intended for a different host to an IP address now connected to your server.

It’s the responsibility of anyone running a web server to handle and reject potentially malicious traffic or unwanted traffic. Ideally, the web server can reject this traffic as early as possible, before it actually reaches the core application code. A reverse proxy is one way to provide this layer of protection for an application server. It can be configured to reject these requests before they reach the application server.

Reverse proxy for performance

Another advantage of using a reverse proxy such as NGINX is that it can be configured to offload some heavy lifting from your application container. For example, every HTTP server should support gzip. Whenever a client requests gzip encoding, the server compresses the response before sending it back to the client. This compression saves network bandwidth, which also improves speed for clients who now don’t have to wait as long for a response to fully download.

NGINX can be configured to accept a plaintext response from your application container and gzip encode it before sending it down to the client. This allows your application container to focus 100% of its CPU allotment on running business logic, while NGINX handles the encoding with its efficient gzip implementation.

An application may have security concerns that require SSL termination at the instance level instead of at the load balancer. NGINX can also be configured to terminate SSL before proxying the request to a local application container. Again, this also removes some CPU load from the application container, allowing it to focus on running business logic. It also gives you a cleaner way to patch any SSL vulnerabilities or update SSL certificates by updating the NGINX container without needing to change the application container.

NGINX configuration

Configuring NGINX for both traffic filtering and gzip encoding is shown below:

http {
  # NGINX will handle gzip compression of responses from the app server
  gzip on;
  gzip_proxied any;
  gzip_types text/plain application/json;
  gzip_min_length 1000;
 
  server {
    listen 80;
 
    # NGINX will reject anything not matching /api
    location /api {
      # Reject requests with unsupported HTTP method
      if ($request_method !~ ^(GET|POST|HEAD|OPTIONS|PUT|DELETE)$) {
        return 405;
      }
 
      # Only requests matching the whitelist expectations will
      # get sent to the application server
      proxy_pass http://app:3000;
      proxy_http_version 1.1;
      proxy_set_header Upgrade $http_upgrade;
      proxy_set_header Connection 'upgrade';
      proxy_set_header Host $host;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_cache_bypass $http_upgrade;
    }
  }
}

The above configuration only accepts traffic that matches the expression /api and has a recognized HTTP method. If the traffic matches, it is forwarded to a local application container accessible at the local hostname app. If the client requested gzip encoding, the plaintext response from that application container is gzip-encoded.

Amazon ECS configuration

Configuring ECS to run this NGINX container as a sidecar is also simple. ECS uses a core primitive called the task definition. Each task definition can include one or more containers, which can be linked to each other:

 {
  "containerDefinitions": [
     {
       "name": "nginx",
       "image": "<NGINX reverse proxy image URL here>",
       "memory": "256",
       "cpu": "256",
       "essential": true,
       "portMappings": [
         {
           "containerPort": "80",
           "protocol": "tcp"
         }
       ],
       "links": [
         "app"
       ]
     },
     {
       "name": "app",
       "image": "<app image URL here>",
       "memory": "256",
       "cpu": "256",
       "essential": true
     }
   ],
   "networkMode": "bridge",
   "family": "application-stack"
}

This task definition causes ECS to start both an NGINX container and an application container on the same instance. Then, the NGINX container is linked to the application container. This allows the NGINX container to send traffic to the application container using the hostname app.

The NGINX container has a port mapping that exposes port 80 on a publically accessible port but the application container does not. This means that the application container is not directly addressable. The only way to send it traffic is to send traffic to the NGINX container, which filters that traffic down. It only forwards to the application container if the traffic passes the whitelisted rules.

Conclusion

Running a sidecar container such as NGINX can bring significant benefits by making it easier to provide protection for application containers. Sidecar containers also improve performance by freeing your application container from various CPU intensive tasks. Amazon ECS makes it easy to run sidecar containers, and automate their deployment across your cluster.

To see the full code for this NGINX sidecar reference, or to try it out yourself, you can check out the open source NGINX reverse proxy reference architecture on GitHub.

– Nathan
 @nathankpeck