CVE-2020-7673
📋 TL;DR
CVE-2020-7673 allows remote code execution through the node-extend library when untrusted user input reaches the vulnerable extend function. This affects any Node.js application using node-extend versions through 0.2.0 that processes external input. Attackers can execute arbitrary code on affected systems.
💻 Affected Systems
- node-extend
📦 What is this software?
Node Extend by Node Extend Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary commands, steal data, install malware, or pivot to other systems.
Likely Case
Remote code execution leading to application compromise, data exfiltration, or service disruption.
If Mitigated
Limited impact if input validation prevents untrusted data from reaching the vulnerable function.
🎯 Exploit Status
Exploitation requires attacker-controlled input to reach the vulnerable function with specific parameters.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.2.1 and later
Vendor Advisory: https://github.com/justmoon/node-extend/security/advisories/GHSA-8c6p-g9qj-8ppj
Restart Required: Yes
Instructions:
1. Update package.json to require node-extend version 0.2.1 or later. 2. Run 'npm update node-extend' or 'yarn upgrade node-extend'. 3. Restart your Node.js application.
🔧 Temporary Workarounds
Input validation and sanitization
allImplement strict input validation to prevent untrusted data from reaching the extend function.
Package lock to safe version
allForce package manager to use patched version by updating package-lock.json or yarn.lock.
npm install node-extend@0.2.1
yarn add node-extend@0.2.1
🧯 If You Can't Patch
- Implement strict input validation and sanitization for all user inputs
- Use network segmentation to isolate vulnerable systems and limit blast radius
🔍 How to Verify
Check if Vulnerable:
Check package.json or run 'npm list node-extend' to see if version is 0.2.0 or earlier.Check Version:
npm list node-extend | grep node-extendVerify Fix Applied:
Verify installed version is 0.2.1 or later using 'npm list node-extend'.📡 Detection & Monitoring
Log Indicators:
- Unusual process spawns from Node.js application
- Suspicious eval() function calls in application logs
Network Indicators:
- Unexpected outbound connections from Node.js application
- Command and control traffic patterns
SIEM Query:
process.name:node AND (process.cmdline:*eval* OR process.cmdline:*child_process*)