CVE-2018-3746
📋 TL;DR
CVE-2018-3746 is a command injection vulnerability in the pdfinfojs NPM module that allows attackers to execute arbitrary commands on the victim's system by injecting malicious input. This affects any application using vulnerable versions of pdfinfojs, particularly Node.js applications that process user-controlled PDF files.
💻 Affected Systems
- pdfinfojs
📦 What is this software?
Pdfinfojs by Pdfinfojs Project
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise allowing attacker to execute arbitrary commands with application privileges, potentially leading to data theft, ransomware deployment, or complete system takeover.
Likely Case
Remote code execution leading to data exfiltration, lateral movement within the network, or installation of backdoors.
If Mitigated
Limited impact due to proper input validation, sandboxing, or network segmentation preventing command execution.
🎯 Exploit Status
Exploitation is straightforward - attacker needs to provide malicious input to PDF processing functions. Public exploit code exists in HackerOne reports.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.3.7 and later
Vendor Advisory: https://www.npmjs.com/advisories/646
Restart Required: Yes
Instructions:
1. Update pdfinfojs to version 0.3.7 or later using 'npm update pdfinfojs'. 2. Restart your Node.js application. 3. Verify the update with 'npm list pdfinfojs'.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation and sanitization for all PDF file inputs before passing to pdfinfojs functions.
Sandbox Execution
allRun the Node.js application in a sandboxed environment with limited permissions to restrict command execution impact.
🧯 If You Can't Patch
- Implement strict input validation to reject any PDF files containing shell metacharacters or suspicious patterns.
- Isolate the vulnerable application in a network segment with no internet access and minimal internal network permissions.
🔍 How to Verify
Check if Vulnerable:
Check package.json or run 'npm list pdfinfojs' to see if version <= 0.3.6 is installed.Check Version:
npm list pdfinfojs | grep pdfinfojsVerify Fix Applied:
Run 'npm list pdfinfojs' and verify version is 0.3.7 or higher. Test PDF processing with known safe files.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in application logs
- PDF processing errors with shell commands in error messages
- Unexpected child process spawns from Node.js application
Network Indicators:
- Outbound connections from Node.js application to unexpected destinations
- Command and control traffic patterns
SIEM Query:
source="application.logs" AND ("pdfinfojs" OR "pdfinfo") AND ("exec" OR "spawn" OR "child_process")