Published: June 2024  
Author: Security Insights by ChatGPT  


When news of a Remote Code Execution (RCE) vulnerability in a popular tool like Visual Studio spreads, developers and infosec professionals pay close attention. CVE-2023-36793 isn’t just another CVE entry: it spotlights how even trusted IDEs can be a launching point for attacks.

Let’s break down CVE-2023-36793—what it means, how it works, and how you can spot or even (safely) test it.

What is CVE-2023-36793?

CVE-2023-36793 affects Microsoft Visual Studio (versions prior to certain fixed releases). The vulnerability allows attackers to execute arbitrary code on the system if a user opens a maliciously crafted file or project within Visual Studio.

The root cause is the way Visual Studio handles certain project or solution files, failing to sufficiently validate user-controlled data, which attackers can exploit to run their own code with the privileges of the user running VS.

How Does the Exploit Work?

An attacker creates a malicious Visual Studio project file (.csproj, .vbproj, etc.) with embedded scripts or manipulated properties. Once an unsuspecting user opens the file, code embedded within or referenced by the project may execute on their system.

Example Exploit Scenario

Say an attacker sends you an open-source C# project repository claiming to fix a bug. Inside, the attacker adds a payload to the .csproj file. When you double-click and load it in VS, the payload silently launches, installing malware or opening a reverse shell.

Dangerous MSBuild Property Exploit Example

One way is through MSBuild tasks in project files. Here’s a simplified, illustrative snippet (do NOT use in a production environment):

<!-- Inside malicious .csproj file -->
<Project Sdk="Microsoft.NET.Sdk">
  <Target Name="MaliciousPayload" AfterTargets="Build">
    <Exec Command="powershell -ExecutionPolicy Bypass -NoProfile -WindowStyle Hidden -Command &amp; {Start-Process notepad}" />
  </Target>
</Project>

When the user opens this project and builds (or sometimes even just loads it), it launches Notepad (could be anything on a real attack).

Microsoft’s Fix

Microsoft’s patches add better validation for files and tighten what gets automatically executed.  
Fixed Versions:

Visual Studio 2017 15.9.57

Upgrade ASAP!  
See the official MSRC advisory for patch downloads.

- Microsoft Security Response Center (MSRC) Advisory
- MITRE CVE Entry
- Visual Studio Update Downloads
- Short write-up example by Certitude

Update Visual Studio to the latest version.

- Use sandboxed/dev VMs for testing unpredictable or open-source repo projects.

Detection Tips

Security-tools (like SentinelOne, Defender ATP) may spot suspicious MSBuild commands running outside normal compile workflows.

Detect possible exploitation with PowerShell (run as admin)

Get-WinEvent -LogName Security | Select-String "MSBuild.exe"

Look for strange invocation patterns, especially those calling external tools (powershell, cmd, curl, etc.).

Conclusion

CVE-2023-36793 isn’t just “theoretical”—it’s a practical route for malware to target developers directly by hijacking their trusted build tools. Make patching your Visual Studio a high priority, scrutinize strange projects, and remember: exploits can hide in code, not just binaries.

For latest updates on Visual Studio security, keep an eye on the MSRC portal and follow security blogs.

Timeline

Published on: 09/12/2023 17:15:00 UTC
Last modified on: 09/12/2023 19:38:00 UTC