The Web Proxy Auto Discovery (WPAD) protocol implementation in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold and 1511, and Internet Explorer 9 through 11 has an improper fallback mechanism, which allows remote attackers to gain privileges via NetBIOS name responses, aka "WPAD Elevation of Privilege Vulnerability."