Listen to this Post
How the CVE Works
The vulnerability in PyPDF arises due to improper handling of FlateDecode streams in manipulated PDF files. An attacker can craft a malicious PDF with a series of nested FlateDecode filters in cross-reference streams. When parsed, PyPDF recursively decompresses these streams without proper memory limits, leading to uncontrolled RAM consumption. Simply opening the file triggers this behavior, while other content streams require explicit access. The lack of decompression size validation allows attackers to exhaust system memory, causing denial-of-service conditions.
DailyCVE Form
Platform: PyPDF
Version: <6.0.0
Vulnerability: Memory exhaustion
Severity: Critical
Date: 2025-08-13
Prediction: Patch expected 2025-08-20
What Undercode Say
Malicious PDF with nested FlateDecode
from pypdf import PdfReader
reader = PdfReader("malicious.pdf") Triggers RAM exhaustion
How Exploit
1. Craft PDF with recursive FlateDecode streams.
2. Distribute or trigger parsing.
3. RAM exhaustion crashes system.
Protection from this CVE
- Upgrade to PyPDF 6.0.0.
- Implement manual decompression checks.
- Limit PDF processing resources.
Impact
- Denial-of-service via RAM exhaustion.
- System instability.
- No remote code execution.
🎯Let’s Practice Exploiting & Learn Patching For Free:
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
