MyBB Threads To Link 1.3 Cross Site Scripting

MyBB Threads to Link plugin version 1.3 suffers from a cross site scripting vulnerability.

MD5 | 052cff4e12c3774b51fd0b1e0b5fde3c

# Exploit Title: MyBB Threads to Link Plugin v1.3 - Persistent XSS
# Date: 3/15/2018
# Author: 0xB9
# Contact: or 0xB9[at]
# Software Link:
# Version: v1.3
# Tested on: Ubuntu 17.10

1. Description:
When editing a thread the user is given to the option to convert the thread to a link.

2. Proof of Concept:

Persistent XSS
- Edit a thread or post you've made
- At the bottom of the edit page in the Thread Link box input the following <a """><SCRIPT>alert("XSS")</SCRIPT>">
- Now visit the forum your thread/post exists in to see the alert.

3. Solution:
The plugin has since been removed after notifying the author.

Patch in line 83:
$thread['tlink'] = ($thread['tlink']);


$thread['tlink'] = htmlspecialchars_uni($thread['tlink']);

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