*June 2024 Exclusive Long-Read*
Visual Studio is one of the world’s most popular integrated development environments (IDE), used by millions of programmers. But did you know that in 2022, a high-severity security hole was discovered that could let hackers remotely execute code on your machine? Today, we break down CVE-2022-29148 — what it is, how it works, and what real-world exploitation could look like.
What is CVE-2022-29148?
CVE-2022-29148 is a Remote Code Execution (RCE) vulnerability that affects several versions of Microsoft Visual Studio. If successfully exploited, an attacker could run code on your machine just by getting you to open a specially crafted solution or project file in Visual Studio.
Official Microsoft Advisory:
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-29148
NVD Entry:
https://nvd.nist.gov/vuln/detail/CVE-2022-29148
Microsoft rated this as important and released patches for it in May 2022.
How Does the Vulnerability Work?
When Visual Studio opens a project or solution file (like .sln or .csproj), it processes its contents for loading references, settings, and configurations. If the file contains maliciously crafted elements, legacy project-loading code in Visual Studio might execute code unexpectedly. This is especially risky if you're using untrusted project files (shared over the internet or email).
The vulnerability is similar in spirit to opening a malicious document in Word or Excel.
How Can It Be Exploited? (Show Me The Code!)
Let's walk through a (simulated) example to understand what an attacker might do.
Crafting a Malicious .csproj File
Visual Studio’s .csproj files are XML-based. An attacker can inject commands in build/target elements. Here’s a simplified example that would open up the Windows Calculator when the project loads:
`
This is not dangerous on its own; Visual Studio and MSBuild will run certain targets as part of the build process. However, in the vulnerable versions of Visual Studio, certain project files could be abused in a way to automatically trigger code execution as soon as the project loads — even before any build command is issued.
Using Solution File Tricks
.sln files can also point to projects with executable code. An attacker could bundle hidden scripts or additional malicious references.
`plaintext
Project("{FAE04EC-301F-11D3-BF4B-00C04F79EFBC}") = "MaliciousProj", "MaliciousProj.csproj", "{8A9A5C6B-1007-45D-BE67-E98F7B123456}"
Dropping and Sharing the Exploit
The attacker zips the .sln and .csproj files and shares it via GitHub, email, or trusted project repositories. Once an unsuspecting developer opens it in a vulnerable Visual Studio installation, boom — attacker’s code runs silently!
Action: Victim double-clicks on the .sln file, Visual Studio opens, no warning.
- Result: Visual Studio processes the malicious XML or project reference and runs hidden code, such as installing malware or adding a new admin user.
Here’s an educational example. Save the following as Exploit.csproj
<Project Sdk="Microsoft.NET.Sdk">
<Target Name="RunMaliciousCode" BeforeTargets="PrepareForBuild">
<Exec Command="powershell -Command "Start-Process notepad.exe"" />
</Target>
</Project>
When this project loads in vulnerable Visual Studio versions, it may automatically execute notepad.exe (or, in the real world, any malicious command).
How Was It Fixed?
Microsoft’s update (May 2022) ensures that Visual Studio now requires user consent before running such suspicious code. If you try to open a malicious project, you’ll get a security prompt or a block.
Download the Patch:
https://my.visualstudio.com/Downloads?q=visual%20studio%202022
Patch ASAP:
Any Visual Studio version before these dates or versions is at risk. See Microsoft’s advisory for specifics.
More Resources & Official Statements
- Microsoft’s Security Update Guide on CVE-2022-29148
- Analyzing malicious .csproj threats (Kaspersky)
- GitHub Advisory Database Entry
Summary
CVE-2022-29148 is a wake-up call for developers: even trusted, everyday tools like Visual Studio can become attack vectors. The fix is simple: patch Visual Studio, watch what you open, and always treat project files like you would any executable file. Stay safe, and happy coding!
_This post is exclusive to you — researched and written in plain language to help all developers stay one step ahead._
Timeline
Published on: 05/10/2022 21:15:00 UTC
Last modified on: 05/19/2022 17:46:00 UTC