A security issue has been reported to us that affects the versions of vBulletin listed here: 5.0.4, 5.0.5, 5.1.0, 5.1.1, and 5.1.2 We have released security patches to account for this vulnerability. The issue may allow attackers to perform SQL injection attacks on your database. It is recommended that all users update as soon as possible.
You can download the patch for your version here: http://members.vbulletin.com/patches.php
As part of our maintenance of Cloud Sites, we will apply the patch to them. If necessary, we will contact Cloud Customers with further information.
The current vBulletin 5.1.3 Alpha will include this fix on its next release. vBulletin 5.1.3 Alpha should not considered suitable for production or live servers.