CVE-2024-56431
📋 TL;DR
CVE-2024-56431 is a disputed vulnerability in libtheora's huffdec.c where oc_huff_tree_unpack contains an invalid negative left shift operation. The vulnerability could potentially lead to memory corruption or crashes when processing malicious Theora video files. This affects applications using libtheora through version 1.0 7180717 for video decoding.
💻 Affected Systems
- libtheora
- applications using libtheora for Theora video decoding
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution or denial of service through crafted Theora video files leading to application crashes or memory corruption.
Likely Case
Application crashes or instability when processing malformed video files, though the security impact is disputed by third parties.
If Mitigated
Limited impact if applications have proper input validation and sandboxing for media processing.
🎯 Exploit Status
Proof of concept available on GitHub demonstrates triggering the invalid shift. However, third parties dispute whether this leads to actual security impact beyond potential crashes.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: https://github.com/xiph/theora/issues/17
Restart Required: No
Instructions:
No official patch available. Monitor the upstream repository for updates. Consider applying community patches if available.
🔧 Temporary Workarounds
Disable Theora video processing
allConfigure applications to avoid using libtheora for Theora video decoding
Application-specific configuration required
Input validation for video files
allImplement strict validation of video files before processing with libtheora
Implement file validation in application code
🧯 If You Can't Patch
- Isolate applications using libtheora in containers or sandboxes
- Implement network segmentation to limit exposure of vulnerable systems
🔍 How to Verify
Check if Vulnerable:
Check libtheora version: `pkg-config --modversion theora` or check installed package versionCheck Version:
pkg-config --modversion theora 2>/dev/null || theora-config --version 2>/dev/null || dpkg -l | grep libtheoraVerify Fix Applied:
Verify libtheora version is newer than 1.0 7180717 when patch becomes available📡 Detection & Monitoring
Log Indicators:
- Application crashes when processing video files
- Memory access violation errors in application logs
Network Indicators:
- Unusual video file uploads to applications
- Repeated failed video processing attempts
SIEM Query:
Application logs containing 'segmentation fault', 'memory corruption', or 'invalid shift' during video processing🔗 References
- https://github.com/UnionTech-Software/libtheora-CVE-2024-56431-PoC
- https://github.com/xiph/theora/blob/7180717276af1ebc7da15c83162d6c5d6203aabf/lib/huffdec.c#L193
- https://github.com/xiph/theora/issues/17#issuecomment-2480630603
- https://www.openwall.com/lists/oss-security/2025/04/25/6
- http://www.openwall.com/lists/oss-security/2025/04/25/4
- http://www.openwall.com/lists/oss-security/2025/04/25/6
