The x86 JIT compiler in Microsoft .NET Framework 2.0 SP2, 3.5 SP1, 3.5.1, and 4.0 does not properly compile function calls, which allows remote attackers to execute arbitrary code via (1) a crafted XAML browser application (aka XBAP), (2) a crafted ASP.NET application, or (3) a crafted .NET Framework application, aka ".NET Framework Stack Corruption Vulnerability."