I would also like to point all concerned to an excellent post about replay attacks on __VIEWSTATE; the post is by Scott Mitchell, the guy who authored the MSDN article I initially referred to [1]: http://scottonwriting.net/sowblog/posts/3747.aspx His article is aimed at developers; Scott explains the issue I reported in a way that makes it perhaps more clear why putting user ID, session ID, or other similar data in __VIEWSTATE is not a remedy by itself, and why reposting __VIEWSTATE is dangerous despite target script location checks. [1] http://msdn.microsoft.com/library/en-us/dnaspp/html/viewstate.asp Cheers, /mz
