[38744] in bugtraq
Re: ASP.NET __VIEWSTATE crypto validation prone to replay attacks
daemon@ATHENA.MIT.EDU (Michal Zalewski)
Fri May 6 11:53:51 2005
Message-ID: <1e89feb305050514177dcf0e27@mail.gmail.com>
Date: Thu, 5 May 2005 23:17:10 +0200
From: Michal Zalewski <lcamtuf@gmail.com>
Reply-To: Michal Zalewski <lcamtuf@gmail.com>
To: bugtraq@securityfocus.com
In-Reply-To: <1e89feb30505051306458c1e4@mail.gmail.com>
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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
