CVE-2025-25473
📋 TL;DR
A memory leak vulnerability exists in FFmpeg's avformat_free_context function, which fails to properly release allocated memory when freeing format contexts. This affects applications using FFmpeg for media processing, potentially leading to resource exhaustion over time. The vulnerability impacts FFmpeg git master versions before commit c08d30.
💻 Affected Systems
- FFmpeg
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Sustained exploitation could lead to memory exhaustion, causing application crashes or denial of service on systems processing large volumes of media files.
Likely Case
Gradual memory consumption increase during media processing operations, potentially causing performance degradation or application instability over extended periods.
If Mitigated
Minimal impact with proper monitoring and restart policies; memory usage returns to normal after process termination.
🎯 Exploit Status
Exploitation requires control over media processing input to trigger repeated context allocations and frees.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: git master commit c08d30 (c08d300481b8ebb846cd43a473988fdbc6793d1b) and later
Vendor Advisory: https://git.ffmpeg.org/gitweb/ffmpeg.git/commit/c08d300481b8ebb846cd43a473988fdbc6793d1b
Restart Required: Yes
Instructions:
1. Update FFmpeg to latest git master (post-commit c08d30). 2. Rebuild from source or obtain patched binaries. 3. Restart all applications using FFmpeg libraries.
🔧 Temporary Workarounds
Memory usage monitoring and restart
linuxMonitor FFmpeg process memory usage and implement automatic restart when thresholds are exceeded
# Example monitoring script
while true; do
ps aux | grep ffmpeg | awk '{print $6}' | while read mem; do
if [ $mem -gt 1000000 ]; then
pkill -f ffmpeg
fi
done
sleep 60
done
Limit media processing batch sizes
allReduce the number of media files processed in single sessions to minimize memory accumulation
# Process files in smaller batches
for file in $(ls *.mp4 | head -10); do
ffmpeg -i "$file" output_${file%.*}.avi
done
🧯 If You Can't Patch
- Implement strict memory usage monitoring with alerting for FFmpeg processes
- Schedule regular application restarts during maintenance windows to clear accumulated memory
🔍 How to Verify
Check if Vulnerable:
Check FFmpeg git commit hash: ffmpeg -version | grep 'git-' or examine source code for commit c08d30 presenceCheck Version:
ffmpeg -version 2>&1 | head -5Verify Fix Applied:
Verify FFmpeg version includes commit c08d30: git log --oneline | grep 'c08d30'📡 Detection & Monitoring
Log Indicators:
- Increasing memory usage patterns in system logs
- FFmpeg process restarts due to memory limits
- Application crashes with out-of-memory errors
Network Indicators:
- Unusual media processing request patterns
- Repeated media file submissions to processing services
SIEM Query:
source="system_logs" (process="ffmpeg" AND (memory>threshold OR "out of memory" OR "killed"))