vBulletin 2.3.4 is a security and bug fix release. We recommend you upgrade as soon as possible; if this is not possible, you can simply use the updated calendar.php from this version to obtain the security fix.

The bugs fixed include:
Problem adding users to buddy/ignore list. (Link)
COPPA profiles visible (Link)
Post titles contain HTML characters when "report bad post" emails (Link)
Security fix in calendar.php


http://www.vbulletin.com/forum/showt...?postid=588825