Executive Summary An elevation of privilege vulnerability exists when Windows improperly handles COM object creation. An attacker who successfully exploited the vulnerability could run arbitrary code with elevated privileges.
To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system.
The update addresses the vulnerability by correcting how the Windows COM Server creates COM objects.
Update & Detail Windows COM Server Elevation of Privilege Vulnerability 
