Effects
MS09-061 is not categorized as virus, worm, Trojan or backdoor. It is a group of critical vulnerabilities in the .NET Common Language Runtime on Windows 7/2008/Vista/2003/XP/2000 computers, which allows arbitrary code to be remotely executed in the vulnerable computer.
The Common Language Runtime (CLR) is a run-time environment provided by the .NET Framework which makes the development process easier.
The affected components are:
- .NET Framework 1.0 on Windows XP.
- .NET Framework 1.1 on Windows 7/2008/Vista/2003/XP/2000.
- .NET Framework 2.0 on Windows 2008/Vista/2003/XP/2000.
The addressed vulnerabilities are:
- Microsoft .NET Framework Pointer Verification vulnerability. it occurs due to the way that .NET verifiable code is verified.
- Microsoft .NET Framework Type Verification vulnerability. it is due to the way that .NET verifiable code is verified.
- Microsoft Silverlight and Microsoft .NET Framework CLR vulnerability: it occurs due to the way that the .NET Common Language Runtime (CLR) handles interfaces.
If exploited successfully, this vulnerability allows hackers to gain remote control of the affected computer with the same privileges as the logged on user. If this user had administrator rights, the hacker could take complete control of the system: create, modify or delete files, install programs, create new user accounts, etc.
This vulnerability can be exploited using different means:
- By creating a specially crafted website that contains a specially crafted XBAP (XAML browser application) or Silverlight application and enticing users to visit it.
- By uploading a malicious ASP.NET application to a web hosting environment.
- By placing a malicious .NET Framework application on a network share and enticing users to execute it.
If you have any of the vulnerable components, it is recommended to download and apply the security patch for this vulnerability. Click here to access the web page for downloading the patch.