This host is missing a critical security update according to Microsoft Bulletin MS11-078.
Successful exploitation could allow attacker to execute arbitrary code within the context of the affected application. Failed exploit attempts will likely result in a denial-of-service condition. Impact Level: System/Application
Run Windows Update and update the listed hotfixes or download and update mentioned hotfixes in the advisory from the below link, http://technet.microsoft.com/en-us/security/bulletin/ms11-078
The flaw due to an error when restricting inheritance within classes and can be exploited via a specially crafted web page.
Microsoft Silverlight 4.0 Microsoft .NET Framework 4.0 Microsoft .NET Framework 3.5.1 Microsoft .NET Framework 2.0 Service Pack 2 Microsoft .NET Framework 1.1 Service Pack 1