Technical Information

Brief overview of the risk:
This security update resolves a privately reported vulnerability in Windows Remote Desktop Client. The vulnerability could allow remote code execution if a user views a specially crafted webpage. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user.
Detailed Information on the risk:

A remote code execution vulnerability exists when the Remote Desktop ActiveX control, mstscax.dll, attempts to access an object in memory that has been deleted. An attacker could exploit the vulnerability by convincing the user to visit a specially crafted webpage. An attacker who successfully exploited this vulnerability could gain the same user rights as the logged-on user

Further information on this exploit is available at : MS13-029