CVE-2020-19667
📋 TL;DR
This CVE describes a stack-based buffer overflow vulnerability in ImageMagick's XPM image processing function. Attackers can exploit this by crafting malicious XPM files to execute arbitrary code or cause denial of service. Systems using vulnerable ImageMagick versions to process untrusted XPM files are affected.
💻 Affected Systems
- ImageMagick
📦 What is this software?
Imagemagick by Imagemagick
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with the privileges of the ImageMagick process, potentially leading to full system compromise.
Likely Case
Denial of service through application crashes when processing malicious XPM files.
If Mitigated
Limited impact if proper input validation and sandboxing prevent malicious file processing.
🎯 Exploit Status
Exploitation requires the victim to process a malicious XPM file. Public proof-of-concept code exists in the GitHub issue.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: ImageMagick 7.0.10-29 and later
Vendor Advisory: https://github.com/ImageMagick/ImageMagick/issues/1895
Restart Required: No
Instructions:
1. Update ImageMagick to version 7.0.10-29 or later. 2. For Debian systems, apply security updates via apt-get update && apt-get upgrade. 3. Rebuild any applications that statically link ImageMagick.
🔧 Temporary Workarounds
Disable XPM coder
linuxRemove XPM support from ImageMagick policy configuration to prevent processing of XPM files.
Edit /etc/ImageMagick-7/policy.xml and add: <policy domain="coder" rights="none" pattern="XPM" />
🧯 If You Can't Patch
- Implement strict input validation to reject or sanitize XPM files before processing.
- Run ImageMagick in a sandboxed environment with minimal privileges to limit exploit impact.
🔍 How to Verify
Check if Vulnerable:
Check ImageMagick version with: convert --version | head -1Check Version:
convert --version | head -1Verify Fix Applied:
Verify version is 7.0.10-29 or higher, or test with a known malicious XPM file (use caution).📡 Detection & Monitoring
Log Indicators:
- ImageMagick process crashes when handling XPM files
- Unusual memory access errors in system logs
Network Indicators:
- Unexpected uploads of XPM files to web applications
SIEM Query:
source="*magick*" AND ("segmentation fault" OR "buffer overflow" OR "XPM")🔗 References
- https://github.com/ImageMagick/ImageMagick/issues/1895
- https://lists.debian.org/debian-lts-announce/2021/01/msg00010.html
- https://lists.debian.org/debian-lts-announce/2023/03/msg00008.html
- https://github.com/ImageMagick/ImageMagick/issues/1895
- https://lists.debian.org/debian-lts-announce/2021/01/msg00010.html
- https://lists.debian.org/debian-lts-announce/2023/03/msg00008.html
