The serialization functionality in Microsoft .NET Framework 2.0 SP2 3.5 3.5 SP1 3.5.1 4 and 4.5 does not properly check the permissions of delegate objects which allows remote attackers to execute arbitrary code via (1) a crafted XAML browser application (XBAP) or (2) a crafted .NET Framework application that leverages a partial-trust relationship aka \Delegate Serialization Vulnerability.\