WHMCS has released new updates for all supported versions of WHMCS. These updates contain changes that address security concerns within the WHMCS product.
We strongly encourage you to update your WHMCS installations as soon as possible.
WHMCS has rated these updates as having important and critical security impacts. Information on security ratings can be found at http://docs.whmcs.com/Security_Levels
Please update your installation to the one of the following versions:
Read more @ http://blog.whmcs.com/?t=81890