CVE-2024-46657
📋 TL;DR
CVE-2024-46657 is a buffer overflow vulnerability in Artifex Software mupdf's pdfextract tool that allows attackers to cause a Denial of Service (DoS) via a specially crafted PDF file. This affects systems running vulnerable versions of mupdf that process untrusted PDF files. The vulnerability is triggered through the pdfextract component when handling malformed PDF input.
💻 Affected Systems
- Artifex Software mupdf
📦 What is this software?
Mupdf by Artifex
⚠️ Risk & Real-World Impact
Worst Case
Complete application crash leading to denial of service for PDF processing functionality, potentially disrupting workflows that rely on mupdf for PDF extraction.
Likely Case
Application segmentation fault causing the pdfextract tool to crash when processing malicious PDF files, resulting in temporary service disruption.
If Mitigated
Minimal impact with proper input validation and sandboxing; crashes would be contained to the pdfextract process without affecting the broader system.
🎯 Exploit Status
Proof-of-concept available in references; exploitation requires the attacker to provide a crafted PDF file to the pdfextract tool. No authentication required if the tool processes external files.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in commit b5c898a30f068b5342e8263a2cd5b9f0be291aac and later versions
Vendor Advisory: https://github.com/ArtifexSoftware/mupdf/commit/b5c898a30f068b5342e8263a2cd5b9f0be291aac
Restart Required: No
Instructions:
1. Update mupdf to version containing commit b5c898a30f068b5342e8263a2cd5b9f0be291aac or later. 2. Rebuild from source if using custom builds. 3. Replace the pdfextract binary with the patched version.
🔧 Temporary Workarounds
Disable pdfextract tool
linuxRemove or disable access to the vulnerable pdfextract binary to prevent exploitation
sudo rm /usr/bin/pdfextract
sudo chmod 000 /usr/bin/pdfextract
Implement PDF file validation
allAdd input validation to reject malformed PDF files before processing with pdfextract
🧯 If You Can't Patch
- Restrict pdfextract tool usage to trusted users only
- Implement sandboxing/containerization to isolate pdfextract process crashes
🔍 How to Verify
Check if Vulnerable:
Check if pdfextract binary exists and test with known malicious PDF sample (use caution). Check mupdf version with 'pdfextract --version' or similar.Check Version:
pdfextract --version 2>/dev/null || strings $(which pdfextract) | grep -i versionVerify Fix Applied:
Verify the mupdf commit hash includes b5c898a30f068b5342e8263a2cd5b9f0be291aac. Test pdfextract with the malicious PDF to confirm no crash.📡 Detection & Monitoring
Log Indicators:
- Segmentation fault errors in system logs related to pdfextract
- Application crash logs showing SIGSEGV for pdfextract process
Network Indicators:
- Unusual PDF file uploads to systems using pdfextract
- Multiple failed PDF processing attempts
SIEM Query:
process_name:"pdfextract" AND (event_type:"crash" OR signal:"SIGSEGV")