CVE-2022-33025
📋 TL;DR
LibreDWG v0.12.4.4608 contains a heap-use-after-free vulnerability in the decode_preR13_section function at decode_r11.c. This allows attackers to potentially execute arbitrary code or cause denial of service by processing specially crafted DWG files. Anyone using LibreDWG to parse DWG files is affected.
💻 Affected Systems
- LibreDWG
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if the application processes malicious DWG files with appropriate memory layout.
Likely Case
Application crash (denial of service) when processing malformed DWG files, potentially leading to data loss or service disruption.
If Mitigated
Limited impact if application runs with minimal privileges and proper sandboxing, though crashes could still occur.
🎯 Exploit Status
Exploitation requires crafting a malicious DWG file that triggers the heap-use-after-free condition; no public exploit code is known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v0.12.5 or later
Vendor Advisory: https://github.com/LibreDWG/libredwg/issues/487
Restart Required: Yes
Instructions:
1. Check current LibreDWG version. 2. Update to v0.12.5 or later via package manager or source compilation. 3. Restart any services using LibreDWG. 4. Verify the fix by checking version.
🔧 Temporary Workarounds
Disable DWG file processing
linuxTemporarily disable LibreDWG's ability to process DWG files until patched
# Remove or rename libredwg binary
sudo mv /usr/bin/dwgread /usr/bin/dwgread.disabled
Input validation
allImplement strict validation of DWG files before processing
# Add file validation in application code
# Example: check file headers before passing to LibreDWG
🧯 If You Can't Patch
- Run LibreDWG in a sandboxed environment with minimal privileges
- Implement network segmentation to isolate systems processing DWG files
🔍 How to Verify
Check if Vulnerable:
Check if LibreDWG version is v0.12.4.4608 or earlier and if DWG file processing is enabledCheck Version:
dwgread --version 2>/dev/null || echo "LibreDWG not found"Verify Fix Applied:
Confirm LibreDWG version is v0.12.5 or later and test with known DWG files📡 Detection & Monitoring
Log Indicators:
- Application crashes with segmentation faults
- Memory access violation errors in system logs
- Unexpected process termination when processing DWG files
Network Indicators:
- Unusual file uploads to DWG processing endpoints
- Multiple failed DWG processing attempts
SIEM Query:
process_name:"dwgread" AND (event_type:"crash" OR exit_code:139)