Tag Archives: windows

Critical Microsoft Code-Execution Vulnerability

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2022/12/critical-microsoft-code-execution-vulnerability.html

A critical code-execution vulnerability in Microsoft Windows was patched in September. It seems that researchers just realized how serious it was (and is):

Like EternalBlue, CVE-2022-37958, as the latest vulnerability is tracked, allows attackers to execute malicious code with no authentication required. Also, like EternalBlue, it’s wormable, meaning that a single exploit can trigger a chain reaction of self-replicating follow-on exploits on other vulnerable systems. The wormability of EternalBlue allowed WannaCry and several other attacks to spread across the world in a matter of minutes with no user interaction required.

But unlike EternalBlue, which could be exploited when using only the SMB, or server message block, a protocol for file and printer sharing and similar network activities, this latest vulnerability is present in a much broader range of network protocols, giving attackers more flexibility than they had when exploiting the older vulnerability.

[…]

Microsoft fixed CVE-2022-37958 in September during its monthly Patch Tuesday rollout of security fixes. At the time, however, Microsoft researchers believed the vulnerability allowed only the disclosure of potentially sensitive information. As such, Microsoft gave the vulnerability a designation of “important.” In the routine course of analyzing vulnerabilities after they’re patched, Palmiotti discovered it allowed for remote code execution in much the way EternalBlue did. Last week, Microsoft revised the designation to critical and gave it a severity rating of 8.1, the same given to EternalBlue.

Microsoft Zero-Days Sold and then Used

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2022/07/microsoft-zero-days-sold-and-then-used.html

Yet another article about cyber-weapons arms manufacturers and their particular supply chain. This one is about Windows and Adobe Reader zero-day exploits sold by an Austrian company named DSIRF.

There’s an entire industry devoted to undermining all of our security. It needs to be stopped.

Interesting Privilege Escalation Vulnerability

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/08/interesting-privilege-escalation-vulnerability.html

If you plug a Razer peripheral (mouse or keyboard, I think) into a Windows 10 or 11 machine, you can use a vulnerability in the Razer Synapse software — which automatically downloads — to gain SYSTEM privileges.

It should be noted that this is a local privilege escalation (LPE) vulnerability, which means that you need to have a Razer devices and physical access to a computer. With that said, the bug is so easy to exploit as you just need to spend $20 on Amazon for Razer mouse and plug it into Windows 10 to become an admin.

Chinese Hackers Stole an NSA Windows Exploit in 2014

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/03/chinese-hackers-stole-an-nsa-windows-exploit-in-2014.html

Check Point has evidence that (probably government affiliated) Chinese hackers stole and cloned an NSA Windows hacking tool years before (probably government affiliated) Russian hackers stole and then published the same tool. Here’s the timeline:

The timeline basically seems to be, according to Check Point:

  • 2013: NSA’s Equation Group developed a set of exploits including one called EpMe that elevates one’s privileges on a vulnerable Windows system to system-administrator level, granting full control. This allows someone with a foothold on a machine to commandeer the whole box.
  • 2014-2015: China’s hacking team code-named APT31, aka Zirconium, developed Jian by, one way or another, cloning EpMe.
  • Early 2017: The Equation Group’s tools were teased and then leaked online by a team calling itself the Shadow Brokers. Around that time, Microsoft cancelled its February Patch Tuesday, identified the vulnerability exploited by EpMe (CVE-2017-0005), and fixed it in a bumper March update. Interestingly enough, Lockheed Martin was credited as alerting Microsoft to the flaw, suggesting it was perhaps used against an American target.
  • Mid 2017: Microsoft quietly fixed the vulnerability exploited by the leaked EpMo exploit.

Lots of news articles about this.

Twelve-Year-Old Vulnerability Found in Windows Defender

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/02/twelve-year-old-vulnerability-found-in-windows-defender.html

Researchers found, and Microsoft has patched, a vulnerability in Windows Defender that has been around for twelve years. There is no evidence that anyone has used the vulnerability during that time.

The flaw, discovered by researchers at the security firm SentinelOne, showed up in a driver that Windows Defender — renamed Microsoft Defender last year — uses to delete the invasive files and infrastructure that malware can create. When the driver removes a malicious file, it replaces it with a new, benign one as a sort of placeholder during remediation. But the researchers discovered that the system doesn’t specifically verify that new file. As a result, an attacker could insert strategic system links that direct the driver to overwrite the wrong file or even run malicious code.

It isn’t unusual that vulnerabilities lie around for this long. They can’t be fixed until someone finds them, and people aren’t always looking.

New Windows Zero-Day

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/11/new-windows-zero-day.html

Google’s Project Zero has discovered and published a buffer overflow vulnerability in the Windows Kernel Cryptography Driver. The exploit doesn’t affect the cryptography, but allows attackers to escalate system privileges:

Attackers were combining an exploit for it with a separate one targeting a recently fixed flaw in Chrome. The former allowed the latter to escape a security sandbox so the latter could execute code on vulnerable machines.

The vulnerability is being exploited in the wild, although Microsoft says it’s not being exploited widely. Everyone expects a fix in the next Patch Tuesday cycle.

Migrating Subversion repositories to AWS CodeCommit

Post Syndicated from Iftikhar khan original https://aws.amazon.com/blogs/devops/migrating-subversion-repositories-aws-codecommit/

In this post, we walk you through migrating Subversion (SVN) repositories to AWS CodeCommit. But before diving into the migration, we do a brief review of SVN and Git based systems such as CodeCommit.

About SVN

SVN is an open-source version control system. Founded in 2000 by CollabNet, Inc., it was originally designed to be a better Concurrent Versions System (CVS), and is being developed as a project of the Apache Software Foundation. SVN is the third implementation of a revision control system: Revision Control System (RCS), then CVS, and finally SVN.

SVN is the leader in centralized version control. Systems such as CVS and SVN have a single remote server of versioned data with individual users operating locally against copies of that data’s version history. Developers commit their changes directly to that central server repository.

All the files and commit history information are stored in a central server, but working on a single central server means more chances of having a single point of failure. SVN offers few offline access features; a developer has to connect to the SVN server to make a commit that makes commits slower. The single point of failure, security, maintenance, and scaling SVN infrastructure are the major concerns for any organization.

About DVCS

Distributed Version Control Systems (DVCSs) address the concerns and challenges of SVN. In a DVCS (such as Git or Mercurial), you don’t just check out the latest snapshot of the files; rather, you fully mirror the repository, including its full history. If any server dies, and these systems are collaborating via that server, you can copy any of the client repositories back up to the server to restore it. Every clone is a full backup of all the data.

DVCs such as Git are built with speed, non-linear development, simplicity, and efficiency in mind. It works very efficiently with large projects, which is one of the biggest factors why customers find it popular.

A significant reason to migrate to Git is branching and merging. Creating a branch is very lightweight, which allows you to work faster and merge easily.

About CodeCommit

CodeCommit is a version control system that is fully managed by AWS. CodeCommit can host secure and highly scalable private Git repositories, which eliminates the need to operate your source control system and scale its infrastructure. You can use it to securely store anything, from source code to binaries. CodeCommit features like collaboration, encryption, and easy access control make it a great choice. It works seamlessly with most existing Git tools and provides free private repositories.

Understanding the repository structure of SVN and Git

SVNs have a tree model with one branch where the revisions are stored, whereas Git uses a graph structure and each commit is a node that knows its parent. When comparing the two, consider the following features:

  • Trunk – An SVN trunk is like a primary branch in a Git repository, and contains tested and stable code.
  • Branches – For SVN, branches are treated as separate entities with its own history. You can merge revisions between branches, but they’re different entities. Because of its centralized nature, all branches are remote. In Git, branches are very cheap; it’s a pointer for a particular commit on the tree. It can be local or be pushed to a remote repository for collaboration.
  • Tags – A tag is just another folder in the main repository in SVN and remains static. In Git, a tag is a static pointer to a specific commit.
  • Commits – To commit in SVN, you need access to the main repository and it creates a new revision in the remote repository. On Git, the commit happens locally, so you don’t need to have access to the remote. You can commit the work locally and then push all the commits at one time.

So far, we have covered how SVN is different from Git-based version control systems and illustrated the layout of SVN repositories. Now it’s time to look at how to migrate SVN repositories to CodeCommit.

Planning for migration

Planning is always a good thing. Before starting your migration, consider the following:

  • Identify SVN branches to migrate.
  • Come up with a branching strategy for CodeCommit and document how you can map SVN branches.
  • Prepare build, test scripts, and test cases for system testing.

If the size of the SVN repository is big enough, consider running all migration commands on the SVN server. This saves time because it eliminates network bottlenecks.

Migrating the SVN repository to CodeCommit

When you’re done with the planning aspects, it’s time to start migrating your code.

Prerequisites

You must have the AWS Command Line Interface (AWS CLI) with an active account and Git installed on the machine that you’re planning to use for migration.

Listing all SVN users for an SVN repository
SVN uses a user name for each commit, whereas Git stores the real name and email address. In this step, we map SVN users to their corresponding Git names and email.

To list all the SVN users, run the following PowerShell command from the root of your local SVN checkout:

svn.exe log --quiet | ? { $_ -notlike '-*' } | % { "{0} = {0} <{0}>" -f ($_ -split ' \| ')[1] } | Select-Object -Unique | Out-File 'authors-transform.txt'

On a Linux based machine, run the following command from the root of your local SVN checkout:

svn log -q | awk -F '|' '/^r/ {sub("^ ", "", $2); sub(" $", "", $2); print $2" = "$2" <"$2">"}' | sort -u > authors-transform.txt

The authors-transform.txt file content looks like the following code:

ikhan = ikhan <ikhan>
foobar= foobar <foobar>
abob = abob <abob>

After you transform the SVN user to a Git user, it should look like the following code:

ikhan = ifti khan <[email protected]>
fbar = foo bar <[email protected]>
abob = aaron bob <[email protected]>

Importing SVN contents to a Git repository

The next step in the migration from SVN to Git is to import the contents of the SVN repository into a new Git repository. We do this with the git svn utility, which is included with most Git distributions. The conversion process can take a significant amount of time for larger repositories.

The git svn clone command transforms the trunk, branches, and tags in your SVN repository into a new Git repository. The command depends on the structure of the SVN.

git svn clone may not be available in all installations; you might consider using an AWS Cloud9 environment or using a temporary Amazon Elastic Compute Cloud (Amazon EC2) instance.

If your SVN layout is standard, use the following command:

git svn clone --stdlayout --authors-file=authors.txt  <svn-repo>/<project> <temp-dir/project>

If your SVN layout isn’t standard, you need to map the trunk, branches, and tags folder in the command as parameters:

git svn clone <svn-repo>/<project> --prefix=svn/ --no-metadata --trunk=<trunk-dir> --branches=<branches-dir>  --tags==<tags-dir>  --authors-file "authors-transform.txt" <temp-dir/project>

Creating a bare Git repository and pushing the local repository

In this step, we create a blank repository and match the default branch with the SVN’s trunk name.

To create the .gitignore file, enter the following code:

cd <temp-dir/project>
git svn show-ignore > .gitignore
git add .gitignore
git commit -m 'Adding .gitignore.'

To create the bare Git repository, enter the following code:

git init --bare <git-project-dir>\local-bare.git
cd <git-project-dir>\local-bare.git
git symbolic-ref HEAD refs/heads/trunk

To update the local bare Git repository, enter the following code:

cd <temp-dir/project>
git remote add bare <git-project-dir\local-bare.git>
git config remote.bare.push 'refs/remotes/*:refs/heads/*'
git push bare

You can also add tags:

cd <git-project-dir\local-bare.git>

For Windows, enter the following code:

git for-each-ref --format='%(refname)' refs/heads/tags | % { $_.Replace('refs/heads/tags/','') } | % { git tag $_ "refs/heads/tags/$_"; git branch -D "tags/$_" }

For Linux, enter the following code:

for t in $(git for-each-ref --format='%(refname:short)' refs/remotes/tags); do git tag ${t/tags\//} $t &amp;&amp; git branch -D -r $t; done

You can also add branches:

cd <git-project-dir\local-bare.git>

For Windows, enter the following code:

git for-each-ref --format='%(refname)' refs/remotes | % { $_.Replace('refs/remotes/','') } | % { git branch "$_" "refs/remotes/$_"; git branch -r -d "$_"; }

For Linux, enter the following code:

for b in $(git for-each-ref --format='%(refname:short)' refs/remotes); do git branch $b refs/remotes/$b && git branch -D -r $b; done

As a final touch-up, enter the following code:

cd <git-project-dir\local-bare.git>
git branch -m trunk master

Creating a CodeCommit repository

You can now create a CodeCommit repository with the following code (make sure that the AWS CLI is configured with your preferred Region and credentials):

aws configure
aws codecommit create-repository --repository-name MySVNRepo --repository-description "SVN Migration repository" --tags Team=Migration

You get the following output:

{
    "repositoryMetadata": {
        "repositoryName": "MySVNRepo",
        "cloneUrlSsh": "ssh://ssh://git-codecommit.us-east-2.amazonaws.com/v1/repos/MySVNRepo",
        "lastModifiedDate": 1446071622.494,
        "repositoryDescription": "SVN Migration repository",
        "cloneUrlHttp": "https://git-codecommit.us-east-2.amazonaws.com/v1/repos/MySVNRepo",
        "creationDate": 1446071622.494,
        "repositoryId": "f7579e13-b83e-4027-aaef-650c0EXAMPLE",
        "Arn": "arn:aws:codecommit:us-east-2:111111111111:MySVNRepo",
        "accountId": "111111111111"
    }
}

Pushing the code to CodeCommit

To push your code to the new CodeCommit repository, enter the following code:

cd <git-project-dir\local-bare.git>
git remote add origin https://git-codecommit.us-east-2.amazonaws.com/v1/repos/MySVNRepo
git add *

git push origin --all
git push origin --tags (Optional if tags are mapped)

Troubleshooting

When migrating SVN repositories, you might encounter a few SVN errors, which are displayed as code on the console. For more information, see Subversion client errors caused by inappropriate repository URL.

For more information about the git-svn utility, see the git-svn documentation.

Conclusion

In this post, we described the straightforward process of using the git-svn utility to migrate SVN repositories to Git or Git-based systems like CodeCommit. After you migrate an SVN repository to CodeCommit, you can use any Git-based client and start using CodeCommit as your primary version control system without worrying about securing and scaling its infrastructure.

Attack Against PC Thunderbolt Port

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/05/attack_against_2.html

The attack requires physical access to the computer, but it’s pretty devastating:

On Thunderbolt-enabled Windows or Linux PCs manufactured before 2019, his technique can bypass the login screen of a sleeping or locked computer — and even its hard disk encryption — to gain full access to the computer’s data. And while his attack in many cases requires opening a target laptop’s case with a screwdriver, it leaves no trace of intrusion and can be pulled off in just a few minutes. That opens a new avenue to what the security industry calls an “evil maid attack,” the threat of any hacker who can get alone time with a computer in, say, a hotel room. Ruytenberg says there’s no easy software fix, only disabling the Thunderbolt port altogether.

“All the evil maid needs to do is unscrew the backplate, attach a device momentarily, reprogram the firmware, reattach the backplate, and the evil maid gets full access to the laptop,” says Ruytenberg, who plans to present his Thunderspy research at the Black Hat security conference this summer­or the virtual conference that may replace it. “All of this can be done in under five minutes.”

Lots of details in the article above, and in the attack website. (We know it’s a modern hack, because it comes with its own website and logo.)

Intel responds.

EDITED TO ADD (5/14): More.