Description

Detects JavaScript code that disables or bypasses XSS protections, allowing reflected cross-site scripting attacks. This vulnerability occurs when user-provided content is rendered without proper sanitization, potentially enabling malicious script injection.

Detection Strategy

• Identifies JavaScript code that explicitly disables XSS protections or security controls

• Detects usage of unsafe content rendering functions or properties that can execute unsanitized content

• Flags instances where user input could be directly rendered into the page without proper escaping

• Checks for dangerous JavaScript patterns that bypass built-in XSS mitigation features

Vulnerable code example

import { Router } from "express";
const router = Router();

router.get("/user", (req, res) => {
  const name = req.query.name;
  // Vulnerable: Direct user input interpolation enables XSS
  res.send(`<h1>Welcome ${name}</h1>`);
});...

✅ Secure code example

import { Router } from "express";
const router = Router();

// Validate and sanitize user input to prevent XSS
function validateName(input = "") {
  const s = String(input);
  // Only allow alphanumeric chars, spaces, dots and dashes, limit length
  return /^[\w .-]{1,100}$/.test(s) ? s : "";...