CVE-2020-28606
📋 TL;DR
This vulnerability in CGAL library allows remote code execution through specially crafted polygon files. Attackers can exploit out-of-bounds read and type confusion vulnerabilities in Nef polygon parsing to execute arbitrary code. Systems using CGAL for computational geometry operations are affected.
💻 Affected Systems
- CGAL (Computational Geometry Algorithms Library)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining complete control over the affected system, potentially leading to data theft, ransomware deployment, or lateral movement.
Likely Case
Application crash leading to denial of service, with potential for limited code execution depending on application context and memory layout.
If Mitigated
Application crash without code execution if memory protections (ASLR, DEP) are effective, but still causing service disruption.
🎯 Exploit Status
Exploitation requires specially crafted polygon files and knowledge of memory layout. No public exploit code has been identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: CGAL-5.1.2 and later
Vendor Advisory: https://www.cgal.org/
Restart Required: Yes
Instructions:
1. Update CGAL to version 5.1.2 or later. 2. Recompile any applications using CGAL. 3. Restart affected services.
🔧 Temporary Workarounds
Input validation
allValidate polygon files before processing with CGAL Nef parser
Disable Nef polygon parsing
allRemove or disable Nef polygon parsing functionality if not required
🧯 If You Can't Patch
- Implement strict input validation for polygon files
- Isolate CGAL processing to dedicated, restricted containers or VMs
🔍 How to Verify
Check if Vulnerable:
Check CGAL version: dpkg -l | grep libcgal or check package managerCheck Version:
cgal_version or check package managerVerify Fix Applied:
Verify CGAL version is 5.1.2 or later📡 Detection & Monitoring
Log Indicators:
- Application crashes when processing polygon files
- Memory access violation errors
Network Indicators:
- Unexpected polygon file uploads to applications using CGAL
SIEM Query:
source="application.log" AND ("segmentation fault" OR "access violation") AND "polygon"🔗 References
- https://lists.debian.org/debian-lts-announce/2022/12/msg00011.html
- https://security.gentoo.org/glsa/202305-34
- https://talosintelligence.com/vulnerability_reports/TALOS-2020-1225
- https://lists.debian.org/debian-lts-announce/2022/12/msg00011.html
- https://security.gentoo.org/glsa/202305-34
- https://talosintelligence.com/vulnerability_reports/TALOS-2020-1225
