CVE-2020-28602
📋 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 within the network.
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 the target's memory layout. No public exploit code has been released.
🛠️ 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
Disable Nef polygon parsing
allDisable or restrict use of Nef polygon parsing functionality in applications
Input validation
allImplement strict validation of polygon file inputs before processing
🧯 If You Can't Patch
- Implement network segmentation to isolate systems using CGAL
- Deploy application allowlisting to prevent execution of unauthorized code
🔍 How to Verify
Check if Vulnerable:
Check CGAL version: dpkg -l | grep libcgal or check package manager for CGAL versionCheck Version:
dpkg -l | grep libcgal # Debian/Ubuntu
rpm -qa | grep cgal # RHEL/CentOSVerify Fix Applied:
Verify CGAL version is 5.1.2 or later and applications have been recompiled📡 Detection & Monitoring
Log Indicators:
- Application crashes when processing polygon files
- Memory access violation errors in application logs
Network Indicators:
- Unexpected polygon file uploads to applications using CGAL
SIEM Query:
source="application.log" AND ("segmentation fault" OR "access violation" OR "out of bounds") AND process="*cgal*"🔗 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
