Microsoft .NET Framework 1.0 SP3 1.1 SP1 2.0 SP2 3.5 3.5.1 4 and 4.5 does not properly check the permissions of objects that use reflection which allows remote attackers to execute arbitrary code via (1) a crafted XAML browser application (XBAP) or (2) a crafted .NET Framework application aka \Delegate Reflection Bypass Vulnerability.\