CVE-2023-37578
📋 TL;DR
CVE-2023-37578 is a use-after-free vulnerability in GTKWave's VCD file parser that allows arbitrary code execution when a malicious .vcd file is opened. Users who open untrusted .vcd files with GTKWave or its vcd2lxt conversion utility are affected. The vulnerability specifically targets the get_vartoken realloc functionality.
💻 Affected Systems
- GTKWave
📦 What is this software?
Gtkwave by Tonybybell
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining the same privileges as the user running GTKWave, potentially leading to data theft, ransomware deployment, or lateral movement.
Likely Case
Local privilege escalation or arbitrary code execution in the context of the user opening the malicious file, potentially compromising sensitive data.
If Mitigated
Denial of service or application crash if exploit fails, with limited impact due to sandboxing or privilege restrictions.
🎯 Exploit Status
Exploitation requires crafting a malicious .vcd file and convincing a user to open it. No public exploit code is known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 3.3.115 (check GTKWave updates)
Vendor Advisory: https://lists.debian.org/debian-lts-announce/2024/04/msg00007.html
Restart Required: No
Instructions:
1. Check for updated GTKWave package from your distribution's repository. 2. For Debian/Ubuntu: sudo apt update && sudo apt upgrade gtkwave. 3. For source installations: Download latest version from official GTKWave website and recompile.
🔧 Temporary Workarounds
Restrict .vcd file handling
allConfigure system to open .vcd files with alternative, unaffected software or disable automatic opening.
User awareness training
allTrain users not to open .vcd files from untrusted sources.
🧯 If You Can't Patch
- Restrict GTKWave and vcd2lxt execution to trusted users only
- Implement application whitelisting to prevent unauthorized GTKWave execution
🔍 How to Verify
Check if Vulnerable:
Check GTKWave version: gtkwave --version or vcd2lxt --version. If version is 3.3.115 or earlier, system is vulnerable.Check Version:
gtkwave --version 2>&1 | head -1Verify Fix Applied:
After update, verify version is newer than 3.3.115 using the same version check command.📡 Detection & Monitoring
Log Indicators:
- Unexpected GTKWave or vcd2lxt process crashes
- Unusual file access patterns to .vcd files
Network Indicators:
- Download of .vcd files from untrusted sources
SIEM Query:
Process creation where (process_name contains 'gtkwave' OR process_name contains 'vcd2lxt') AND command_line contains '.vcd'🔗 References
- https://lists.debian.org/debian-lts-announce/2024/04/msg00007.html
- https://talosintelligence.com/vulnerability_reports/TALOS-2023-1806
- https://lists.debian.org/debian-lts-announce/2024/04/msg00007.html
- https://talosintelligence.com/vulnerability_reports/TALOS-2023-1806
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2023-1806
