CVE-2025-27091
📋 TL;DR
A heap overflow vulnerability in OpenH264 video codec library allows remote attackers to crash applications or potentially execute arbitrary code by tricking users into processing malicious video files. This affects all systems using OpenH264 version 2.5.0 or earlier for video decoding. Both AVC and SVC encoding modes are vulnerable.
💻 Affected Systems
- OpenH264 codec library
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise via heap overflow exploitation
Likely Case
Application crashes and denial of service when processing malicious video content
If Mitigated
Limited to denial of service if exploit fails to achieve code execution
🎯 Exploit Status
Exploitation requires crafting malicious video bitstreams and user interaction to process them. Race condition makes reliable exploitation challenging.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.6.0 and later
Vendor Advisory: https://github.com/cisco/openh264/security/advisories/GHSA-m99q-5j7x-7m9x
Restart Required: No
Instructions:
1. Download OpenH264 version 2.6.0 or later from GitHub releases. 2. Replace existing OpenH264 library files with patched version. 3. Recompile applications if statically linked. 4. Restart applications using OpenH264.
🔧 Temporary Workarounds
No known workarounds
allThe vendor advisory states there are no known workarounds for this vulnerability
🧯 If You Can't Patch
- Disable video processing features that use OpenH264 in affected applications
- Implement strict input validation and sandboxing for video processing components
🔍 How to Verify
Check if Vulnerable:
Check OpenH264 library version. If version is 2.5.0 or earlier, system is vulnerable.Check Version:
ldd /path/to/application | grep openh264 or check library version directlyVerify Fix Applied:
Verify OpenH264 version is 2.6.0 or later. Test with known malicious video samples if available.📡 Detection & Monitoring
Log Indicators:
- Application crashes during video processing
- Memory access violation errors
- Heap corruption warnings
Network Indicators:
- Unusual video file transfers
- Video processing from untrusted sources
SIEM Query:
Application:openh264 AND (EventID:1000 OR EventID:1001) OR Process:openh264 AND ExceptionCode:c0000005