MyBB Delete Account Plugin 1.4 - Cross-Site Scripting

# Exploit Title: MyBB Delete Account Plugin 1.4 - Cross-Site Scripting
# Date: 1/25/2021
# Author: 0xB9
# Twitter: @0xB9Sec
# Contact: 0xB9[at]pm.me
# Software Link: https://github.com/vintagedaddyo/MyBB_Plugin-Delete_Account/
# Version: 1.4
# Tested on: Windows 10

1. Description:
This plugin allows users to delete their account. Giving a reason for deleting your account is vulnerable to XSS.

2. Proof of Concept:

- Go to User CP -> Delete Account
- Input a payload for delete account reason   <script>alert('XSS')</script>
Payload will execute here.. admin/index.php?module=user-deleteaccount