CVE-2020-22336
📋 TL;DR
CVE-2020-22336 is a stack buffer overflow vulnerability in pdfcrack's MD5 function that allows attackers to execute arbitrary code. This affects pdfcrack versions 0.17 through 0.18. Users running vulnerable versions of pdfcrack are at risk of remote code execution.
💻 Affected Systems
- pdfcrack
📦 What is this software?
Pdfcrack by Pdfcrack Project
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining root privileges and persistent access to the affected system.
Likely Case
Remote code execution leading to data theft, system manipulation, or installation of malware/backdoors.
If Mitigated
Limited impact if system is isolated, has strict network controls, and runs with minimal privileges.
🎯 Exploit Status
The stack overflow vulnerability is straightforward to exploit given the public bug reports and source code availability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.19 or later
Vendor Advisory: https://sourceforge.net/p/pdfcrack/bugs/12/
Restart Required: No
Instructions:
1. Download pdfcrack 0.19 or later from the official source. 2. Uninstall the vulnerable version. 3. Install the patched version following the installation instructions.
🔧 Temporary Workarounds
Remove pdfcrack
linuxUninstall pdfcrack if not required for operations
sudo apt remove pdfcrack
sudo yum remove pdfcrack
Restrict execution
linuxRemove execute permissions from pdfcrack binary
sudo chmod -x $(which pdfcrack)
🧯 If You Can't Patch
- Run pdfcrack in a sandboxed/containerized environment with minimal privileges
- Implement strict network segmentation to limit access to systems running pdfcrack
🔍 How to Verify
Check if Vulnerable:
Check pdfcrack version with 'pdfcrack --version' or 'dpkg -l | grep pdfcrack'Check Version:
pdfcrack --versionVerify Fix Applied:
Verify installed version is 0.19 or later using 'pdfcrack --version'📡 Detection & Monitoring
Log Indicators:
- Unusual process execution patterns from pdfcrack
- Memory violation errors in system logs
Network Indicators:
- Unexpected network connections originating from systems running pdfcrack
SIEM Query:
process.name:"pdfcrack" AND (event.action:"process_start" OR event.action:"memory_violation")