MyBB KingChat Plugin - SQL Injection

# Exploit Title: KingChat MyBB plugin SQL Injection 0day
# Google Dork: inurl:"kingchat.php"
# Date: 13.10.2012
# Exploit Author: Red_Hat [NullSec]
# Software Link: http://mods.mybb.com/view/kingchat
# Tested on: Windows & Linux.

Vulnerable code :

<?php
	$username=$_GET['username'];
	$uid=$_GET['uid'];
	$text=$_GET['text'];

					$users=$db->query("SELECT * FROM ".TABLE_PREFIX."users WHERE username='$username'");
					$users_info=$db->fetch_array($users);
					$users_num=$db->num_rows($users);
					$fusername=$users_info['uid'];
?>

The variable '$username' remains unsanitized.

Usage : http://www.site.com/kingchat.php?send=Red_Hat&username=[SQLi]

Shoutout to Zixem <3 & NullSec :3