Textpattern CMS 4.9.0-dev - 'Excerpt' Persistent Cross-Site Scripting (XSS)

# Exploit Title:  Textpattern CMS 4.9.0-dev - 'Excerpt' Persistent Cross-Site Scripting (XSS)
# Date: 2021-03-04
# Exploit Author: Tushar Vaidya
# Vendor Homepage: https://textpattern.com
# Software Link: https://textpattern.com/start
# Version: v 4.9.0-dev
# Tested on: Windows

Steps-To-Reproduce:
1. Login into Textpattern CMS admin panel.
2. Now go to the *Content > Write > ** Excerpt*.
3. Now paste the below payload in the URL field.

Ba1man”><img src=x onerror=confirm(document.cookie)>

4. Now click on the *Save* button.
5. Now go to the *articles* page
5. The XSS will be triggered.