- Perform a cross-site scripting attack that breaks out of the JavaScript string and calls the
alert function.
- 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.
- Replace your input with the following payload to break out of the script block and inject a new script:
</script><script>alert(1)</script>
- 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.