# Exploit Title: Extended Useradmininfo MyBB Plugin 1.2.1 - Cross Site
Scripting
# Google Dork: N/A
# Date: 09.02.2014
# Exploit Author: Fikri Fadzil - fikri.fadzil@impact-alliance.org
# Vendor Homepage: http://forum.mybboard.de/user-9022.html
# Software Link: http://mods.mybb.com/view/extended-useradmininfo
# Version: 1.2.1
# Tested on: PHP

Description:
This plugin shows advanced Informations about a user, such as last IP, User
Agent, Browser and Operating System. The information will be shown in a
user profile and visible only  for people who are able to see the
adminoptions on user profiles.

Proof of Concept
1. Create a user account.
2. Change your user-agent to "Mozilla<script>alert(1)</script>".
3. Login and then... logout.

* The script will be executed whenever the administrator view your profile.


Solution:
Replace the content of "inc/plugins/extendeduseradmininfos.php" with this
fix:
http://pastebin.com/ncQCvwdq