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."