CVE-2024-42358
📋 TL;DR
CVE-2024-42358 is a denial-of-service vulnerability in PDFio's TTF parser where maliciously crafted TrueType font files cause infinite loops and memory exhaustion. This affects any application using PDFio library to parse PDF files containing TTF fonts, including web servers that convert PDF submissions to plaintext. The vulnerability can lead to complete service disruption through resource exhaustion.
💻 Affected Systems
- PDFio library
- Applications using PDFio for PDF processing
📦 What is this software?
Pdfio by Msweet
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service with 100% memory utilization and infinite loops, potentially leading to heap buffer overflow and system instability or crashes.
Likely Case
Service disruption through resource exhaustion when processing malicious TTF files, causing affected applications to become unresponsive.
If Mitigated
Limited impact with proper input validation and resource limits, but still vulnerable to targeted DoS attacks.
🎯 Exploit Status
Exploitation requires only a malicious TTF file; no authentication needed. The advisory provides technical details but no public exploit code.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.3.1
Vendor Advisory: https://github.com/michaelrsweet/pdfio/security/advisories/GHSA-4hh9-j68x-8353
Restart Required: Yes
Instructions:
1. Identify applications using PDFio. 2. Update PDFio to version 1.3.1 or later. 3. Rebuild applications if PDFio is statically linked. 4. Restart affected services.
🧯 If You Can't Patch
- Implement strict input validation to reject suspicious TTF files before processing
- Deploy resource limits (memory, CPU timeouts) on processes using PDFio to contain DoS impact
🔍 How to Verify
Check if Vulnerable:
Check if PDFio version is below 1.3.1 using 'pdfio --version' or examine application dependencies.Check Version:
pdfio --versionVerify Fix Applied:
Confirm PDFio version is 1.3.1 or higher and test with known malicious TTF files to ensure no infinite loops occur.📡 Detection & Monitoring
Log Indicators:
- High memory usage spikes
- Processes stuck at 100% CPU for extended periods
- Application crashes when processing PDF/TTF files
Network Indicators:
- Unusual PDF/TTF file uploads to web services
- Increased error rates in PDF processing services
SIEM Query:
source="application_logs" AND ("memory exhaustion" OR "infinite loop" OR "pdfio")