CVE-2020-20898
📋 TL;DR
An integer overflow vulnerability in FFmpeg's convolution filter allows attackers to cause denial of service or potentially execute arbitrary code by processing specially crafted video files. This affects systems using FFmpeg 4.2.1 for video processing. Applications that use FFmpeg libraries for video filtering are vulnerable.
💻 Affected Systems
- FFmpeg
📦 What is this software?
Ffmpeg by Ffmpeg
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if the integer overflow enables memory corruption that can be weaponized.
Likely Case
Denial of service causing FFmpeg process crashes when processing malicious video files.
If Mitigated
Limited impact with proper input validation and sandboxing of FFmpeg processes.
🎯 Exploit Status
Exploitation requires crafting a malicious video file that triggers the integer overflow in the convolution filter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in commit 99f8d32129dd233d4eb2efa44678a0bc44869f23
Vendor Advisory: https://trac.ffmpeg.org/ticket/8263
Restart Required: Yes
Instructions:
1. Update FFmpeg to version with the fix commit. 2. Recompile any applications using FFmpeg libraries. 3. Restart affected services.
🔧 Temporary Workarounds
Disable convolution filter
allPrevent use of the vulnerable filter16_prewitt function
Modify FFmpeg configuration to exclude convolution filter usage
Input validation
allImplement strict input validation for video files before processing
Implement file type/size validation in applications using FFmpeg
🧯 If You Can't Patch
- Sandbox FFmpeg processes with minimal privileges
- Implement network segmentation to isolate FFmpeg processing systems
🔍 How to Verify
Check if Vulnerable:
Check FFmpeg version: ffmpeg -version | grep 'version'Check Version:
ffmpeg -version | head -1Verify Fix Applied:
Verify FFmpeg version is newer than 4.2.1 or includes commit 99f8d32129dd233d4eb2efa44678a0bc44869f23📡 Detection & Monitoring
Log Indicators:
- FFmpeg process crashes
- Segmentation fault errors in system logs
- Abnormal termination of video processing services
Network Indicators:
- Unusual video file uploads to processing systems
- Repeated failed video processing requests
SIEM Query:
source="*ffmpeg*" AND ("segmentation fault" OR "SIGSEGV" OR "crash")