Technical Information

Brief overview of the risk:
This security update resolves one privately reported vulnerability in the .NET Framework. The vulnerability could allow elevation of privilege if a user views a specially crafted webpage using a web browser that can run XAML Browser Applications (XBAPs). The vulnerability could also be used by Windows .NET applications to bypass Code Access Security (CAS) restrictions. An attacker who successfully exploited this vulnerability could gain the same user rights as the current user.
Detailed Information on the risk:

An elevation of privilege vulnerability exists in the way that the .NET Framework elevates the permissions of a callback function when a particular Windows Forms object is created. An attacker who successfully exploited this vulnerability could take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

Further information on this exploit is available at : MS13-015