CVE-2011-3416high
Description
The Forms Authentication feature in the ASP.NET subsystem in Microsoft .NET Framework 1.1 SP1, 2.0 SP2, 3.5 SP1, 3.5.1, and 4.0 allows remote authenticated users to obtain access to arbitrary user accounts via a crafted username, aka "ASP.Net Forms Authentication Bypass Vulnerability."
References
http://www.us-cert.gov/cas/techalerts/TA11-347A.html
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-100
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14363