Microsoft Windows XP SP2 and SP3 Windows Server 2003 SP2 Windows Vista SP2 Windows Server 2008 SP2 and R2 SP1 Windows 7 SP1 Windows 8 Windows 8.1 Windows Server 2012 Gold and R2 and Windows RT Gold and 8.1 allow remote attackers to cause a denial of service (daemon hang) via a web-service request containing a crafted X.509 certificate that is not properly handled during validation aka \Digital Signatures Vulnerability.\