CVE-2023-28102
📋 TL;DR
This vulnerability in discordrb (a Ruby Discord API library) allows command injection if user-controlled input reaches a specific method. Attackers could execute arbitrary shell commands on the host system. Only applications using discordrb with unsafe user input in the vulnerable method are affected.
💻 Affected Systems
- discordrb
📦 What is this software?
Discordrb by Discordrb Project
⚠️ Risk & Real-World Impact
Worst Case
Full compromise of the host system with the privileges of the discordrb process, potentially leading to data theft, ransomware deployment, or complete system takeover.
Likely Case
Limited command execution within the application's process context, potentially accessing application data or performing lateral movement within the environment.
If Mitigated
No impact if proper input validation/sanitization is implemented or if the vulnerable method isn't called with user input.
🎯 Exploit Status
Exploitation requires the client application to pass unsanitized user input to the vulnerable method. No public exploit code has been released.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Commit 91e13043ffa89227c3fcdc3408f06da237d28c95
Vendor Advisory: https://securitylab.github.com/advisories/GHSL-2022-094_discordrb/
Restart Required: Yes
Instructions:
1. Update discordrb to the patched version from GitHub (no new gem release available). 2. Replace vulnerable encoder.rb with the patched version. 3. Restart the application.
🔧 Temporary Workarounds
Input Validation/Sanitization
allImplement strict input validation and sanitization for any user input passed to discordrb methods.
Avoid User Input in Vulnerable Method
allEnsure the vulnerable method is not called with any user-controlled input.
🧯 If You Can't Patch
- Implement strict input validation and sanitization for all user inputs passed to discordrb.
- Run the discordrb process with minimal privileges (non-root, restricted user account).
🔍 How to Verify
Check if Vulnerable:
Check if your discordrb version is before commit 91e13043ffa. Review application code to see if user input reaches the encoder.rb file methods.Check Version:
Check Gemfile.lock or run 'gem list discordrb' to see installed version, then compare with GitHub commit history.Verify Fix Applied:
Verify the discordrb installation uses the patched encoder.rb file from commit 91e13043ffa or later.📡 Detection & Monitoring
Log Indicators:
- Unexpected shell command execution from the discordrb process
- Process spawning with unusual arguments
Network Indicators:
- Outbound connections from the discordrb process to unexpected destinations
SIEM Query:
Process creation events where parent process is the discordrb application and command line contains suspicious shell metacharacters🔗 References
- https://github.com/shardlab/discordrb/commit/91e13043ffa89227c3fcdc3408f06da237d28c95
- https://securitylab.github.com/advisories/GHSL-2022-094_discordrb/
- https://github.com/shardlab/discordrb/commit/91e13043ffa89227c3fcdc3408f06da237d28c95
- https://securitylab.github.com/advisories/GHSL-2022-094_discordrb/
