CVE-2025-25467
📋 TL;DR
This critical memory management vulnerability in libx264 allows attackers to execute arbitrary code by processing a specially crafted AAC file. Any application or system using the vulnerable libx264 library for video encoding/decoding is affected. This includes media processing servers, video editing software, and streaming applications.
💻 Affected Systems
- libx264
- Applications using libx264 library
- FFmpeg with x264 support
- VideoLAN VLC media player
- Various media processing tools
⚠️ 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
Full remote code execution with the privileges of the application using libx264, potentially leading to complete system compromise, data theft, or ransomware deployment.
Likely Case
Remote code execution on media processing servers, allowing attackers to pivot to internal networks, steal sensitive data, or deploy malware.
If Mitigated
Denial of service through application crashes if memory corruption occurs but code execution fails.
🎯 Exploit Status
Exploitation requires crafting a malicious AAC file that triggers the memory management flaw. No public exploit code is currently available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: libx264 git commit with fix (check upstream repository)
Vendor Advisory: https://code.videolan.org/videolan/x264/-/issues/75
Restart Required: Yes
Instructions:
1. Update libx264 from official repository. 2. Rebuild applications using libx264. 3. Restart affected services. 4. Verify the fix with test files.
🔧 Temporary Workarounds
Disable AAC processing
allConfigure applications to avoid processing AAC files with libx264
Application-specific configuration required
Input validation
allImplement file type validation before passing to libx264
Implement file signature checking in application code
🧯 If You Can't Patch
- Network segmentation to isolate media processing systems
- Implement strict file upload controls and scanning for AAC files
🔍 How to Verify
Check if Vulnerable:
Check libx264 version and build date against patched versions. Test with known safe AAC files.Check Version:
x264 --version | grep versionVerify Fix Applied:
Verify libx264 version is updated and test processing of various AAC files without crashes.📡 Detection & Monitoring
Log Indicators:
- Application crashes when processing AAC files
- Memory allocation errors in system logs
- Unusual process spawning from media applications
Network Indicators:
- Unexpected outbound connections from media servers
- Large AAC file uploads to processing endpoints
SIEM Query:
source="application_logs" AND ("segmentation fault" OR "memory corruption" OR "libx264") AND file_type="aac"