CVE-2023-36274
📋 TL;DR
CVE-2023-36274 is a heap buffer overflow vulnerability in LibreDWG's bit_write_TF function that allows attackers to execute arbitrary code or cause denial of service. This affects systems using LibreDWG v0.11 to v0.12.5 for processing DWG files. Users and applications that handle untrusted DWG files are at risk.
💻 Affected Systems
- LibreDWG
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or ransomware deployment
Likely Case
Application crash (denial of service) when processing malicious DWG files
If Mitigated
Limited impact with proper sandboxing and file validation controls
🎯 Exploit Status
Proof-of-concept exists in GitHub issues. Exploitation requires crafting a malicious DWG file that triggers the buffer overflow when processed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v0.12.6 and later
Vendor Advisory: https://github.com/LibreDWG/libredwg/commit/8651fa27dd2de731e706e2ba09f0d28e4e0dce33
Restart Required: Yes
Instructions:
1. Update LibreDWG to version 0.12.6 or later. 2. Rebuild any applications using LibreDWG. 3. Restart services using the library.
🔧 Temporary Workarounds
Disable DWG file processing
allTemporarily disable LibreDWG functionality or block DWG file uploads/processing
Sandbox LibreDWG processes
linuxRun LibreDWG in isolated containers with limited permissions
docker run --read-only --cap-drop=ALL -v /tmp:/tmp:ro your_app
🧯 If You Can't Patch
- Implement strict file validation: reject malformed DWG files before processing
- Deploy application sandboxing with minimal privileges and network restrictions
🔍 How to Verify
Check if Vulnerable:
Check LibreDWG version: libredwg --version or examine library filesCheck Version:
libredwg --version 2>/dev/null || strings /usr/lib/libredwg.so | grep 'libredwg'Verify Fix Applied:
Confirm version is 0.12.6 or later and test with known malicious DWG files📡 Detection & Monitoring
Log Indicators:
- Segmentation faults in LibreDWG processes
- Abnormal memory usage patterns
- Repeated crashes when processing DWG files
Network Indicators:
- Unusual DWG file uploads to web applications
- Large DWG files triggering processing errors
SIEM Query:
process_name:"libredwg" AND (event_type:"crash" OR memory_usage:>threshold)