The host is installed with Microsoft Windows Vista SP2, Server 2008 SP2, Windows 7 SP1, Server 2008 R2 SP1, Windows 8, Server 2012, Windows 8.1 or Server 2012 R2 and is prone to a security feature bypass vulnerability. A flaw is present in the Windows kernel-mode driver, which fails to properly validate and enforce impersonation levels. An attacker who successfully exploited this vulnerability could bypass impersonation-level security and gain elevated privileges on a targeted system.