This lab's verbose error messages reveal that it is using a vulnerable version of a third-party framework. To solve the lab, obtain and submit the version number of this framework.
In Burp, go to "Proxy" > "HTTP history" and notice that the GET request for product pages contains a productID parameter. Send the GET /product?productId=1 request to Burp Repeater. Note that your productId might be different depending on which product page you loaded.
In Burp Repeater, change the value of the productId parameter to a non-integer data type, such as a string. Send the request.
GET /product?productId="example"
The unexpected data type causes an exception, and a full stack trace is displayed in the response. This reveals that the lab is using Apache Struts 2 2.3.31.
Go back to the lab, click "Submit solution", and enter 2 2.3.31 to solve the lab.
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