CVE-2019-5087
📋 TL;DR
An integer overflow vulnerability in xcftools allows memory corruption when processing specially crafted XCF files. This could lead to arbitrary code execution with the privileges of the user running xcf2png or xcf2pnm. Users of xcftools 1.0.7 who process untrusted XCF files are affected.
💻 Affected Systems
- xcftools
📦 What is this software?
Xcftools by Xcftools Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if exploited against a privileged user or service.
Likely Case
Local privilege escalation or denial of service when processing malicious XCF files.
If Mitigated
Limited impact if proper file validation and privilege separation are implemented.
🎯 Exploit Status
Exploitation requires user interaction to open malicious XCF file. Proof of concept available in Talos advisory.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.0.8 or later
Vendor Advisory: https://lists.debian.org/debian-lts-announce/2021/02/msg00014.html
Restart Required: No
Instructions:
1. Update xcftools to version 1.0.8 or later using package manager. 2. For Debian/Ubuntu: sudo apt update && sudo apt upgrade xcftools. 3. For source installation: Download latest version from official repository and recompile.
🔧 Temporary Workarounds
Remove vulnerable binaries
linuxRemove or restrict access to xcf2png and xcf2pnm binaries
sudo rm /usr/bin/xcf2png
sudo rm /usr/bin/xcf2pnm
Restrict file processing
allImplement file validation to reject untrusted XCF files
🧯 If You Can't Patch
- Implement strict file upload validation to reject XCF files from untrusted sources
- Run xcftools in sandboxed environment with minimal privileges
🔍 How to Verify
Check if Vulnerable:
Check xcftools version: xcftools --version | grep '1.0.7'Check Version:
xcftools --versionVerify Fix Applied:
Verify version is 1.0.8 or later: xcftools --version📡 Detection & Monitoring
Log Indicators:
- Process crashes of xcf2png or xcf2pnm
- Unusual memory allocation patterns
Network Indicators:
- None - local file processing vulnerability
SIEM Query:
process_name IN ('xcf2png', 'xcf2pnm') AND exit_code != 0🔗 References
- https://lists.debian.org/debian-lts-announce/2021/02/msg00014.html
- https://lists.debian.org/debian-lts-announce/2021/03/msg00008.html
- https://talosintelligence.com/vulnerability_reports/TALOS-2019-0879
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2019-0879
- https://lists.debian.org/debian-lts-announce/2021/02/msg00014.html
- https://lists.debian.org/debian-lts-announce/2021/03/msg00008.html
- https://talosintelligence.com/vulnerability_reports/TALOS-2019-0879
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2019-0879
