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."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A17430
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2013/ms13-052