Unspecified vulnerability in Citrix XenServer 6.2 Service Pack 1 and earlier allows attackers to cause a denial of service and obtain sensitive information by modifying the guest virtual hard disk (VHD).
https://exchange.xforce.ibmcloud.com/vulnerabilities/94632
http://www.securitytracker.com/id/1030604
http://www.securityfocus.com/bid/68660