CVE-2020-22029
📋 TL;DR
This is a heap-based buffer overflow vulnerability in FFmpeg's colorconstancy filter that allows attackers to cause memory corruption by processing specially crafted video files. It affects FFmpeg 4.2 installations that use the colorconstancy filter. Successful exploitation could lead to arbitrary code execution or denial of service.
💻 Affected Systems
- FFmpeg
📦 What is this software?
Ffmpeg by Ffmpeg
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with the privileges of the FFmpeg process, potentially leading to complete system compromise.
Likely Case
Application crash (denial of service) when processing malicious video files.
If Mitigated
No impact if the vulnerable filter is disabled or patched versions are used.
🎯 Exploit Status
Exploitation requires crafting a malicious video file that triggers the buffer overflow when processed with the vulnerable filter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in commit a7fd1279703683ebb548ef7baa2f1519994496ae and later versions
Vendor Advisory: https://www.debian.org/security/2021/dsa-4990
Restart Required: No
Instructions:
1. Update FFmpeg to version 4.2.3 or later. 2. For source installations: apply commit a7fd1279703683ebb548ef7baa2f1519994496ae. 3. Recompile if using source build.
🔧 Temporary Workarounds
Disable colorconstancy filter
allPrevent use of the vulnerable filter in FFmpeg commands
Avoid using '-vf colorconstancy' in FFmpeg commands
Input validation
allValidate and sanitize video file inputs before processing
🧯 If You Can't Patch
- Disable or restrict use of FFmpeg's colorconstancy filter in all applications
- Implement strict input validation for video files and use sandboxing for FFmpeg processes
🔍 How to Verify
Check if Vulnerable:
Check FFmpeg version: ffmpeg -version | grep 'version' and verify if it's 4.2.x. Also check if colorconstancy filter is available: ffmpeg -filters | grep colorconstancyCheck Version:
ffmpeg -version | head -1Verify Fix Applied:
Verify FFmpeg version is 4.2.3 or later, or check git commit hash includes a7fd1279703683ebb548ef7baa2f1519994496ae📡 Detection & Monitoring
Log Indicators:
- FFmpeg process crashes with segmentation faults
- Memory corruption errors in system logs when processing video files
Network Indicators:
- Unusual video file uploads to media processing services
- Large number of failed video processing requests
SIEM Query:
Process:ffmpeg AND (EventID:1000 OR Signal:SIGSEGV) OR Process:ffmpeg AND CommandLine:"*colorconstancy*"🔗 References
- http://git.videolan.org/?p=ffmpeg.git%3Ba=commitdiff%3Bh=a7fd1279703683ebb548ef7baa2f1519994496ae
- https://trac.ffmpeg.org/ticket/8250
- https://www.debian.org/security/2021/dsa-4990
- http://git.videolan.org/?p=ffmpeg.git%3Ba=commitdiff%3Bh=a7fd1279703683ebb548ef7baa2f1519994496ae
- https://trac.ffmpeg.org/ticket/8250
- https://www.debian.org/security/2021/dsa-4990
