Official Information:
http://www.vbulletin.com/forum/showthread.php?t=319572
-:: The Advisory ::-
The "Home Page" field in the user profile was only checking the user input
for either "www" or the following regular expression written in normal text:
Any letter from A to Z and/or a number from 0-9 + :// will make the link valid.
The output in the Home Page field is encoded with most likely htmlspecialchars(),
however before the patch it did not check if a user would create a link that
