An elevation of privilege vulnerability exists in the Microsoft Windows Update Client when it does not properly handle privileges. An attacker who successfully exploited this vulnerability could run processes in an elevated context. An attacker could then install programs; view, change or delete data.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 security update addresses the vulnerability by enabling the Windows Update client to properly handle user privileges.