CVE-2020-28494
📋 TL;DR
This vulnerability allows remote command injection in total.js framework versions before 3.4.7. Attackers can execute arbitrary commands on the server by exploiting insufficient input sanitization in image processing functions. Any application using vulnerable total.js versions with image.pipe or image.stream functions is affected.
💻 Affected Systems
- total.js framework
📦 What is this software?
Total.js by Totaljs
⚠️ Risk & Real-World Impact
Worst Case
Full server compromise allowing arbitrary command execution, data exfiltration, lateral movement, and persistent backdoor installation.
Likely Case
Remote code execution leading to application takeover, data theft, or cryptocurrency mining malware deployment.
If Mitigated
Limited impact if proper input validation and command sanitization are implemented, potentially reduced to denial of service.
🎯 Exploit Status
Exploitation requires minimal technical skill due to public proof-of-concept and simple command injection pattern.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.4.7 and later
Vendor Advisory: https://github.com/totaljs/framework/commit/6192491ab2631e7c1d317c221f18ea613e2c18a5
Restart Required: Yes
Instructions:
1. Update total.js package: npm update total.js
2. Verify version is 3.4.7 or higher
3. Restart the Node.js application
4. Test image processing functionality
🔧 Temporary Workarounds
Input validation wrapper
allAdd custom input validation for image.pipe and image.stream parameters
// Add validation before calling image functions
const validateType = (type) => {
const allowed = ['png', 'jpg', 'jpeg', 'gif'];
if (!allowed.includes(type.toLowerCase())) {
throw new Error('Invalid image type');
}
return type;
}
🧯 If You Can't Patch
- Implement strict input validation for all image processing parameters
- Disable or restrict access to image processing endpoints if not essential
🔍 How to Verify
Check if Vulnerable:
Check package.json for total.js version <3.4.7 or run: npm list total.jsCheck Version:
npm list total.js | grep total.jsVerify Fix Applied:
Verify total.js version is >=3.4.7 and test image processing with malicious input📡 Detection & Monitoring
Log Indicators:
- Unusual child_process.spawn commands in logs
- Image processing requests with shell metacharacters
- Unexpected system command execution
Network Indicators:
- HTTP requests to image endpoints containing shell commands
- Unusual outbound connections from Node.js process
SIEM Query:
process.name:node.exe AND cmdline:*spawn* AND cmdline:*shell*