CVE-2024-7867
📋 TL;DR
This vulnerability in Xpdf allows attackers to cause integer overflow and divide-by-zero errors by providing malicious PDF files with very large coordinates in page boxes. This can lead to denial of service (crash) or potentially arbitrary code execution. Anyone using Xpdf 4.05 or earlier to process untrusted PDF files is affected.
💻 Affected Systems
- Xpdf
📦 What is this software?
Xpdf by Xpdfreader
⚠️ Risk & Real-World Impact
Worst Case
Arbitrary code execution leading to complete system compromise if the integer overflow can be leveraged for memory corruption attacks.
Likely Case
Denial of service through application crash when processing malicious PDF files.
If Mitigated
Limited impact if Xpdf is sandboxed or runs with minimal privileges, though crashes may still occur.
🎯 Exploit Status
Exploitation requires providing a malicious PDF file to Xpdf. No authentication is needed if the application processes user-supplied files.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.06
Vendor Advisory: https://www.xpdfreader.com/security-bug/CVE-2024-7867.html
Restart Required: No
Instructions:
1. Download Xpdf 4.06 from https://www.xpdfreader.com/download.html. 2. Replace existing Xpdf binaries with the new version. 3. Recompile any applications that use Xpdf libraries with the updated version.
🔧 Temporary Workarounds
Input validation for PDF files
allImplement server-side validation to reject PDF files with suspiciously large coordinate values before passing to Xpdf.
Sandbox Xpdf execution
linuxRun Xpdf in a container or sandbox with limited privileges to contain potential exploitation.
docker run --read-only --cap-drop=ALL -v /path/to/pdf:/pdf:ro xpdf xpdf /pdf/file.pdf
🧯 If You Can't Patch
- Restrict Xpdf to only process trusted PDF files from known sources.
- Implement monitoring for Xpdf crashes and alert on unusual activity.
🔍 How to Verify
Check if Vulnerable:
Check Xpdf version with 'xpdf -v' or 'pdftotext -v'. If version is 4.05 or earlier, the system is vulnerable.Check Version:
xpdf -v 2>&1 | head -1Verify Fix Applied:
After updating, verify version shows 4.06 or later with the same commands.📡 Detection & Monitoring
Log Indicators:
- Xpdf crash logs
- Segmentation fault errors in system logs when processing PDFs
- Unexpected process termination of Xpdf
Network Indicators:
- Unusual PDF file uploads to web applications
- Multiple failed PDF processing attempts
SIEM Query:
process_name:"xpdf" AND (event_type:crash OR exit_code:139)