Canonicalization security bug in ASP.NET
As many people know, there has been a lot of talk about a security bug in ASP.NET running on Windows 2000. Microsoft has just announced information regarding this bug. Here are some urls that I suggest you look into.
http://support.microsoft.com/?kbid=887459
http://www.microsoft.com/security/incident/aspnet.mspx
http://www.asp.net/Forums/ShowForum.aspx?tabindex=1&ForumID=25
http://www.asp.net/Forums/ShowPost.aspx?tabindex=1&PostID=709506