XSS payload: '"()%26%25<yes><ScRiPt%20>alert(1)</ScRiPt>
1- Login to Fork admin panel
2- Goto Modules=>Formbuilder
3- Turn on Burp Intercept
4- Click on "Update Filter"
5- Change value of "start_date" parameter to 22/03/2021'"()%26%25<yes><ScRiPt%20>alert(1)</ScRiPt>
6- Forward the request and XSS will be triggered
Video POC: https://drive.google.com/file/d/12PqUfuw3RFyOcFS0HIHfTkxrpsDDtACd/view?usp=sharing
With the help of xss attacker can perform social engineering on users by redirecting them from real website to fake one. Attacker can steal their cookies leading to account takeover and download a malware on their system, and there are many more attacking scenarios a skilled attacker can perform with xss.