Microsoft Internet Explorer 8 does not properly handle objects in memory, which allows remote attackers to execute arbitrary code by accessing an object that (1) was not properly allocated or (2) is deleted, as exploited in the wild in May 2013.
The WCF Replace function in the Open Data (aka OData) protocol implementation in Microsoft .NET Framework 3.5, 3.5 SP1, 3.5.1, and 4, and the Management OData IIS Extension on Windows Server 2012, allows remote attackers to cause a denial of service (resource consumption and daemon restart) via crafted values in HTTP requests, aka "Replace Denial of Service Vulnerability."
The Windows Forms (aka WinForms) component in Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, and 4.5 does not properly restrict the privileges of a callback function during object creation, which allows remote attackers to execute arbitrary code via (1) a crafted XAML browser application (XBAP) or (2) a crafted .NET Framework application, aka "WinForms Callback Elevation Vulnerability."