CVE-2023-27390
📋 TL;DR
A heap-based buffer overflow vulnerability in Diagon's Sequence::DrawText function allows arbitrary code execution when processing malicious markdown files. Users who open specially crafted files with vulnerable Diagon versions are affected. This is a client-side vulnerability requiring user interaction.
💻 Affected Systems
- Diagon
📦 What is this software?
Diagon by Diagon Project
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining the same privileges as the user running Diagon, potentially leading to data theft, ransomware deployment, or lateral movement.
Likely Case
Local privilege escalation leading to user account compromise, file system access, and potential credential harvesting.
If Mitigated
Limited impact if application runs with minimal privileges, sandboxed, or in isolated environments.
🎯 Exploit Status
Exploitation requires user to open malicious file. No public exploit code available at time of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Diagon releases after v1.0.139
Vendor Advisory: https://github.com/ArthurSonzogni/Diagon/releases
Restart Required: Yes
Instructions:
1. Visit Diagon GitHub releases page
2. Download latest version
3. Uninstall old version
4. Install new version
5. Restart system
🔧 Temporary Workarounds
Disable file processing
allPrevent Diagon from opening markdown files
Use application sandboxing
allRun Diagon in restricted environment
🧯 If You Can't Patch
- Restrict Diagon to trusted users only
- Implement application whitelisting to prevent execution
🔍 How to Verify
Check if Vulnerable:
Check Diagon version - if v1.0.139 or earlier, assume vulnerableCheck Version:
diagon --version or check About menuVerify Fix Applied:
Verify installed version is newer than v1.0.139📡 Detection & Monitoring
Log Indicators:
- Crash logs from Diagon
- Unexpected process termination
Network Indicators:
- None - local file exploitation
SIEM Query:
Process:Diagon AND (EventID:1000 OR EventID:1001)