CVE-2021-25944
📋 TL;DR
CVE-2021-25944 is a prototype pollution vulnerability in the 'deep-defaults' npm package versions 1.0.0 through 1.0.5. This allows attackers to modify object prototypes, potentially leading to denial of service or remote code execution. Any application using these vulnerable versions is affected.
💻 Affected Systems
- deep-defaults npm package
📦 What is this software?
Deep Defaults by Deep Defaults Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or ransomware deployment.
Likely Case
Denial of service through application crashes or instability, with potential for limited code execution in specific configurations.
If Mitigated
Limited impact if input validation and sandboxing prevent prototype pollution exploitation.
🎯 Exploit Status
Prototype pollution vulnerabilities are well-understood with public proof-of-concept code available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.0.6 and later
Vendor Advisory: https://www.npmjs.com/advisories/1741
Restart Required: Yes
Instructions:
1. Update package.json to specify 'deep-defaults': '^1.0.6' 2. Run 'npm update deep-defaults' 3. Restart all Node.js applications using this package 4. Test application functionality
🔧 Temporary Workarounds
Input validation and sanitization
allImplement strict input validation to prevent malicious object manipulation
Package replacement
allReplace deep-defaults with alternative libraries like lodash.defaultsdeep
npm uninstall deep-defaults
npm install lodash.defaultsdeep
🧯 If You Can't Patch
- Implement WAF rules to detect and block prototype pollution patterns
- Isolate affected applications in network segments with strict egress filtering
🔍 How to Verify
Check if Vulnerable:
Check package.json or package-lock.json for deep-defaults version 1.0.0-1.0.5, or run 'npm list deep-defaults'Check Version:
npm list deep-defaults | grep deep-defaultsVerify Fix Applied:
Confirm deep-defaults version is 1.0.6+ with 'npm list deep-defaults' and test application with known exploit payloads📡 Detection & Monitoring
Log Indicators:
- Unexpected application crashes
- Unusual object property modifications
- Memory exhaustion errors
Network Indicators:
- HTTP requests with specially crafted JSON objects
- Unusual outbound connections from Node.js processes
SIEM Query:
process.name:node.exe AND (event_data.CommandLine:*deep-defaults* OR event_data.ImagePath:*node*)