CVE-2019-14493
📋 TL;DR
CVE-2019-14493 is a NULL pointer dereference vulnerability in OpenCV's XML parser that can cause denial of service (crash) when processing malicious XML files. This affects applications using OpenCV's persistence module to parse XML data. Developers and systems using OpenCV for image processing with XML configuration or data files are impacted.
💻 Affected Systems
- OpenCV
📦 What is this software?
Opencv by Opencv
⚠️ Risk & Real-World Impact
Worst Case
Complete application crash leading to denial of service, potentially disrupting critical image processing pipelines or services.
Likely Case
Application crash when processing specially crafted XML files, causing temporary service disruption.
If Mitigated
Minimal impact with proper input validation and error handling; crashes contained within isolated processes.
🎯 Exploit Status
Exploitation requires feeding malicious XML to the vulnerable parser. Public proof-of-concept exists in GitHub issues.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: OpenCV 4.1.1 and later
Vendor Advisory: https://github.com/opencv/opencv/issues/15127
Restart Required: Yes
Instructions:
1. Update OpenCV to version 4.1.1 or later. 2. Recompile applications against the updated library. 3. Restart affected services.
🔧 Temporary Workarounds
Disable XML parsing
allRemove or disable XML parsing functionality if not required
Recompile with XML persistence disabled or modify code to avoid cv::XMLParser usage
Input validation
allValidate XML files before passing to OpenCV parser
Implement XML schema validation or use separate XML library for validation
🧯 If You Can't Patch
- Implement strict input validation for all XML files processed by OpenCV
- Run OpenCV applications in isolated containers with resource limits to contain crashes
🔍 How to Verify
Check if Vulnerable:
Check OpenCV version: if version < 4.1.1 and application uses XML parsing, it's vulnerableCheck Version:
python -c "import cv2; print(cv2.__version__)" or check build configurationVerify Fix Applied:
Verify OpenCV version is ≥ 4.1.1 and test with known malicious XML samples📡 Detection & Monitoring
Log Indicators:
- Application crashes with segmentation faults
- Error messages mentioning persistence.cpp or XMLParser
Network Indicators:
- Unusual XML file uploads to image processing services
- Repeated requests with XML payloads
SIEM Query:
source="application.log" AND ("segmentation fault" OR "NULL pointer" OR "persistence.cpp")🔗 References
- https://github.com/opencv/opencv/compare/371bba8...ddbd10c
- https://github.com/opencv/opencv/issues/15127
- https://lists.debian.org/debian-lts-announce/2021/10/msg00028.html
- https://github.com/opencv/opencv/compare/371bba8...ddbd10c
- https://github.com/opencv/opencv/issues/15127
- https://lists.debian.org/debian-lts-announce/2021/10/msg00028.html
