Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, and 4.5, and Silverlight 5 before 5.1.20513.0, does not properly prevent changes to data in multidimensional arrays of structures, which allows remote attackers to execute arbitrary code via (1) a crafted .NET Framework application or (2) a crafted Silverlight application, aka "Array Access Violation Vulnerability."