CVE-2018-16489
📋 TL;DR
A prototype pollution vulnerability in just-extend versions before 4.0.0 allows attackers to inject arbitrary properties into Object.prototype through library functions. This affects any application using vulnerable versions of the just-extend JavaScript utility library, potentially enabling various attack vectors.
💻 Affected Systems
- just-extend
📦 What is this software?
Just Extend by Just Extend Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution, complete application compromise, or denial of service through prototype pollution leading to arbitrary code execution.
Likely Case
Application instability, denial of service, or privilege escalation through property injection affecting application logic.
If Mitigated
Limited impact if input validation and sanitization are implemented, though prototype pollution remains a risk.
🎯 Exploit Status
Exploitation requires attacker-controlled input to vulnerable just-extend functions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.0.0
Vendor Advisory: https://www.npmjs.com/advisories/786
Restart Required: No
Instructions:
1. Update just-extend to version 4.0.0 or later. 2. Run: npm update just-extend. 3. Test application functionality.
🔧 Temporary Workarounds
Input validation and sanitization
allImplement strict input validation and sanitization for all user inputs passed to just-extend functions.
🧯 If You Can't Patch
- Implement strict input validation and sanitization for all user inputs.
- Use object property whitelisting instead of blacklisting in application code.
🔍 How to Verify
Check if Vulnerable:
Check package.json or run: npm list just-extendCheck Version:
npm list just-extendVerify Fix Applied:
Verify just-extend version is 4.0.0 or later: npm list just-extend📡 Detection & Monitoring
Log Indicators:
- Unusual property injections
- Application crashes or instability
Network Indicators:
- Suspicious input patterns in HTTP requests
SIEM Query:
Search for application errors or crashes related to just-extend or prototype pollution.