Story of a JSON XSS
Hi folks, This post is about of one of my recent my finding in a bug bounty program. I started checking the application for common vulnerabilities but got nothing after spending an hour I came across an endpoint which looks as follows. If you look at request and response you will see the value of status parameter is reflecting back in the response. So I tried replacing the value of status parameter and same reflected back in the response as shown in below. What next? Let’s check for XSS with a simple payload as shown in below. But angle brackets getting filtered, after I tried some encodings but nothing worked. So I was about to give up but suddenly i decided to try array tricks. So you can see whatever we write inside the round brackets is reflecting back in response as it becomes associated array as follows Status Equals JSON object <haha> Equals Key of JSON o...