MyBB <1.6.9 is vulnerable to Stored, Error based, SQL Injection.
 
Vulnerable code:
 
/editpost.php
 
===
Line 398
===
$posthash_query = "posthash='{$posthash}' OR ";
===
 
 
It can be done by using Tamper Data(Or Live HTTP Headers), and when
submitting a post, edit the 'posthash' POST parameter to your payload,
submitting, then going to edit your post.
 
 
Small "HOWTO" in picture: http://imgur.com/a/JxfEI
 
This bug was not found by me, but afaik, I am the first one to release it.
 
 
-- 
*Joshua Rogers* - Retro Game Collector && IT Security Specialist
gpg pubkey <http://www.internot.info/docs/gpg_pubkey.asc.gpg>