Bugtraq mailing list archives
Re: ASP.NET __VIEWSTATE crypto validation prone to replay attacks
From: Michal Zalewski <lcamtuf () gmail com>
Date: Thu, 5 May 2005 22:06:21 +0200
Microsoft has addressed your issues 1-a, 1-b and 1-c by adding a property "ViewStateUserKey" to the System.Web.UI.Page class in .NET Framework 1.1. The documentation for this property is here:
No, I think this statement is simply not true. The key is intended to solve a wholly different class of problems, and has nothing to do with replay attacks I reported. Reported issue 1-a: same user moves __VIEWSTATE from one page to another. Adding unique user identifier to __VIEWSTATE does not help, because in both cases, it's precisely the same user within the same system. Reported issue 1-b: same user retains __VIEWSTATE and reuses it at a later date. Again, it's precisely the same person and the same unique ID. Reported issue 1-c: this is the least relevant of all reported problems, and indeed can be in some situations mitigated by binding __VIEWSTATE data to a specific user. /mz
Current thread:
- ASP.NET __VIEWSTATE crypto validation prone to replay attacks Michal Zalewski (May 03)
- Re: ASP.NET __VIEWSTATE crypto validation prone to replay attacks H D Moore (May 05)
- <Possible follow-ups>
- RE: ASP.NET __VIEWSTATE crypto validation prone to replay attacks Tim Farley (May 05)
- Re: ASP.NET __VIEWSTATE crypto validation prone to replay attacks Michal Zalewski (May 05)
- Re: ASP.NET __VIEWSTATE crypto validation prone to replay attacks Michal Zalewski (May 06)
- Re: ASP.NET __VIEWSTATE crypto validation prone to replay attacks Anton Ivanov (May 12)
- Re: ASP.NET __VIEWSTATE crypto validation prone to replay attacks Michal Zalewski (May 06)