MyBB Like Plugin 3.0.0 - Cross-Site Scripting

# Exploit Title: MyBB Like Plugin 3.0.0 - Cross-Site Scripting
# Date: 2018-08-01
# Author: 0xB9
# Twitter: @0xB9Sec
# Software Link: https://community.mybb.com/mods.php?action=view&pid=360
# Version: 3.0.0
# Tested on: Ubuntu 18.04
# CVE: N/A

# 1. Description:
# This plugin allows users to thank/like other users threads/posts. 
# In user profiles it shows your most liked post/thread, the post/thread 
# subjects aren't sanitized to user input.
 
# 2. Proof of Concept:

- Use the following as the post/thread subject  <script>alert('XSS')</script>
- Get that post/thread liked by another user (or you)
- Visit your profile to see alert.