CVE-2020-21830
📋 TL;DR
A heap-based buffer overflow vulnerability in GNU LibreDWG 0.10 allows attackers to execute arbitrary code or cause denial of service by processing specially crafted DWG files. This affects any application or service that uses LibreDWG to handle DWG CAD files. Users and systems processing untrusted DWG files are at risk.
💻 Affected Systems
- GNU LibreDWG
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with the privileges of the LibreDWG process, potentially leading to full system compromise.
Likely Case
Application crash (denial of service) when processing malicious DWG files, with potential for code execution in some scenarios.
If Mitigated
Limited to denial of service if exploit fails or memory protections are in place.
🎯 Exploit Status
Exploitation requires crafting a malicious DWG file; public proof-of-concept exists in GitHub issue #188.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 0.10.1 or later
Vendor Advisory: https://github.com/LibreDWG/libredwg/issues/188
Restart Required: No
Instructions:
1. Update LibreDWG to version 0.10.1 or later. 2. Recompile any applications using LibreDWG libraries. 3. Replace vulnerable binaries with patched versions.
🔧 Temporary Workarounds
Disable DWG file processing
allTemporarily block or reject DWG files from untrusted sources.
Use alternative DWG viewer
allSwitch to a different, non-vulnerable DWG processing library or application.
🧯 If You Can't Patch
- Restrict access to LibreDWG applications to trusted users only.
- Implement strict file upload validation to reject suspicious DWG files.
🔍 How to Verify
Check if Vulnerable:
Check LibreDWG version: `dwgread --version` or examine linked library versions in applications.Check Version:
dwgread --versionVerify Fix Applied:
Confirm version is 0.10.1 or later and test with known malicious DWG samples if available.📡 Detection & Monitoring
Log Indicators:
- Application crashes or abnormal terminations when processing DWG files
- Memory access violation errors in system logs
Network Indicators:
- Unusual file uploads of DWG files to web services
SIEM Query:
source="application.log" AND ("segmentation fault" OR "buffer overflow") AND "libredwg"