Microsoft .NET Framework 1.0 SP3, 1.1 SP1, 2.0 SP2, 3.5, 3.5.1, 4, 4.5, and 4.5.1 does not properly determine whether it is safe to execute a method, which allows remote attackers to execute arbitrary code via (1) a crafted web site or (2) a crafted .NET Framework application that exposes a COM server endpoint, aka "Type Traversal Vulnerability."