CVE-2025-62707
📋 TL;DR
CVE-2025-62707 is a denial-of-service vulnerability in pypdf, a popular Python PDF library. Attackers can craft malicious PDFs with inline images using DCTDecode filters that cause infinite loops during parsing, leading to resource exhaustion. This affects any application using vulnerable versions of pypdf to process untrusted PDF files.
💻 Affected Systems
- pypdf
📦 What is this software?
Pypdf by Pypdf Project
⚠️ Risk & Real-World Impact
Worst Case
Complete denial-of-service where the application becomes unresponsive, consumes all available CPU resources, and requires process termination.
Likely Case
Application hangs or crashes when processing malicious PDFs, disrupting PDF-related functionality.
If Mitigated
Minimal impact with proper input validation and resource limits in place.
🎯 Exploit Status
Exploitation requires only a malicious PDF file; no authentication or special privileges needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.1.3
Vendor Advisory: https://github.com/py-pdf/pypdf/security/advisories/GHSA-vr63-x8vc-m265
Restart Required: No
Instructions:
1. Update pypdf using pip: pip install --upgrade pypdf==6.1.3
2. Verify the update with: pip show pypdf
3. Test PDF processing functionality after update.
🔧 Temporary Workarounds
Input validation and sanitization
allImplement strict validation of PDF files before processing, rejecting files with suspicious inline image structures.
Resource limiting
allSet CPU time limits or process timeouts for PDF parsing operations to prevent infinite loops from consuming resources.
🧯 If You Can't Patch
- Implement strict file upload controls to only accept PDFs from trusted sources.
- Deploy web application firewalls (WAF) with PDF parsing protection rules.
🔍 How to Verify
Check if Vulnerable:
Check pypdf version with: pip show pypdf | grep VersionCheck Version:
pip show pypdf | grep VersionVerify Fix Applied:
Confirm version is 6.1.3 or higher with: pip show pypdf | grep Version📡 Detection & Monitoring
Log Indicators:
- High CPU usage spikes during PDF processing
- Application timeouts or crashes when handling PDF files
- Repeated PDF parsing errors
Network Indicators:
- Multiple PDF upload attempts from single source
- Unusual PDF file sizes or structures
SIEM Query:
source="application.logs" AND ("pypdf" OR "PDF parsing") AND ("timeout" OR "high cpu" OR "crash")