The Common Language Runtime (CLR) in Microsoft .NET Framework 2.0 SP1 2.0 SP2 3.5 3.5 SP1 and 3.5.1 and Microsoft Silverlight 2 and 3 before 3.0.50611.0 on Windows and before 3.0.41130.0 on Mac OS X does not properly handle interfaces and delegations to virtual methods which allows remote attackers to execute arbitrary code via (1) a crafted XAML browser application (aka XBAP) (2) a crafted ASP.NET application or (3) a crafted .NET Framework application aka \Microsoft Silverlight and Microsoft .NET Framework CLR Virtual Method Delegate Vulnerability.\