CVE-2025-62708
📋 TL;DR
CVE-2025-62708 is a memory exhaustion vulnerability in pypdf, a popular Python PDF library. Attackers can craft malicious PDFs with LZWDecode filters that cause excessive memory consumption when parsed. This affects any application using vulnerable versions of pypdf to process PDF files.
💻 Affected Systems
- pypdf
📦 What is this software?
Pypdf by Pypdf Project
⚠️ Risk & Real-World Impact
Worst Case
Denial of service causing application crashes, system instability, or resource exhaustion leading to service unavailability.
Likely Case
Application crashes or degraded performance when processing malicious PDFs, potentially disrupting PDF-related functionality.
If Mitigated
Minimal impact with proper input validation and resource limits, though PDF processing may fail gracefully.
🎯 Exploit Status
Exploitation requires only a crafted PDF file. No authentication needed if PDF processing is exposed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.1.3
Vendor Advisory: https://github.com/py-pdf/pypdf/security/advisories/GHSA-jfx9-29x2-rv3j
Restart Required: No
Instructions:
1. Update pypdf: pip install --upgrade pypdf==6.1.3
2. Verify installation: pip show pypdf
3. Test PDF processing functionality after update.
🔧 Temporary Workarounds
Disable LZWDecode Filter Processing
allModify code to reject or skip PDFs using LZWDecode filters before parsing.
# Python code to check for LZWDecode filter
# Inspect PDF metadata before processing
Implement Resource Limits
linuxSet memory limits on PDF processing functions using resource management.
# Use Python's resource module or container limits
import resource
resource.setrlimit(resource.RLIMIT_AS, (max_memory, max_memory))
🧯 If You Can't Patch
- Implement strict input validation to reject suspicious PDF files before processing.
- Deploy PDF processing in isolated containers with strict memory limits and monitoring.
🔍 How to Verify
Check if Vulnerable:
Check pypdf version: pip show pypdf | grep Version. If version is <6.1.3, system is vulnerable.Check Version:
pip show pypdf | grep VersionVerify Fix Applied:
Confirm pypdf version is 6.1.3 or higher and test PDF processing with known safe files.📡 Detection & Monitoring
Log Indicators:
- Application crashes during PDF processing
- High memory usage spikes from PDF-related processes
- Errors mentioning LZWDecode or memory allocation
Network Indicators:
- Multiple PDF uploads to vulnerable endpoints
- Unusual PDF file sizes or patterns
SIEM Query:
source="application.log" AND ("pypdf" OR "PDF") AND ("crash" OR "memory" OR "LZWDecode")