- Vulnerability in the search query tracking functionality where angle brackets and double are HTML encoded and single quotes are escaped.
- Submit a random alphanumeric string in the search box, then use Burp Suite to intercept the search request and send it to Burp Repeater.
- Observe that the random string has been reflected inside a JavaScript string.
- Try sending the payload
test'payload and observe that your single quote gets backslash-escaped, preventing you from breaking out of the string.
- Try sending the payload
test\payload and observe that your backslash doesn’t get escaped.
- Replace your input with the following payload to break out of the JavaScript string and inject an alert:
\'-alert(1)//
- Verify the technique worked by right clicking, selecting “Copy URL”, and pasting the URL in the browser. When you load the page it should trigger an alert.