CVE-2025-63918
📋 TL;DR
PDFPatcher contains a directory traversal vulnerability (CWE-22) where the executable fails to validate user-supplied file paths, allowing attackers to write arbitrary files to arbitrary locations on the system. This affects users who process untrusted PDF files with vulnerable versions of PDFPatcher.
💻 Affected Systems
- PDFPatcher
📦 What is this software?
Pdfpatcher by Cnblogs
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise via arbitrary file write leading to remote code execution, data theft, or ransomware deployment.
Likely Case
File system manipulation allowing data exfiltration, privilege escalation, or persistence mechanisms installation.
If Mitigated
Limited impact if application runs with minimal privileges and file system permissions restrict write access to sensitive locations.
🎯 Exploit Status
Exploitation requires user to open a malicious PDF file. Public proof-of-concept exists in GitHub repository.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://github.com/wmjordan/PDFPatcher
Restart Required: No
Instructions:
1. Monitor GitHub repository for security updates. 2. Check if maintainer has released patched version. 3. Update to latest secure version when available.
🔧 Temporary Workarounds
Restrict PDFPatcher Execution
allLimit PDFPatcher usage to trusted environments and users only.
Run with Minimal Privileges
allExecute PDFPatcher with non-administrative/low-privilege user account.
🧯 If You Can't Patch
- Discontinue use of PDFPatcher for processing untrusted PDF files.
- Implement application whitelisting to prevent PDFPatcher execution in sensitive environments.
🔍 How to Verify
Check if Vulnerable:
Check if PDFPatcher version is unpatched by testing with proof-of-concept PDF from GitHub repository.Check Version:
Run PDFPatcher with --version or -v flag, or check About dialog in GUI.Verify Fix Applied:
Test with same proof-of-concept PDF after update - traversal attempts should be blocked.📡 Detection & Monitoring
Log Indicators:
- File write operations to unexpected directories
- PDFPatcher process writing outside expected export directories
- Path traversal patterns in file operations (../ sequences)
Network Indicators:
- Unusual outbound connections following PDF processing
- File transfers from systems running PDFPatcher
SIEM Query:
Process:PDFPatcher AND (FileWrite:*/../* OR FileWrite:*..\*)