An elevation of privilege exists when Winlogon does not properly handle file path information. An attacker who successfully exploited this vulnerability could run arbitrary code. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.
To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application to take control of an affected system.
The update addresses the vulnerability by correcting how Winlogon handles path information.