For our existing clients with WordPress sites, we installed the recent updates to WordPress as they became available. For WordPress 3.42, this was done on September 7th, 2012. WordPress 3.42 fixes 21 different security problems that have been reported. WordPress 3.5 was released December 12, 2012.
These updates to security problems are one of the valuable features of WordPress. Without these updates, hackers will exploit the security gaps in a web-site to take control.