Unspecified vulnerability in a guest virtual device driver in VMware Workstation before 5.5.9 build 126128, and 6.5.1 and earlier 6.x versions; VMware Player before 1.0.9 build 126128, and 2.5.1 and earlier 2.x versions; VMware ACE before 1.0.8 build 125922, and 2.5.1 and earlier 2.x versions; VMware Server 1.x before 1.0.8 build 126538 and 2.0.x before 2.0.1 build 156745; VMware Fusion before 2.0.1; VMware ESXi 3.5; and VMware ESX 3.0.2, 3.0.3, and 3.5 allows guest OS users to cause a denial of service (host OS crash) via unknown vectors.

hcmon.sys in VMware Workstation 6.5.1 and earlier, VMware Player 2.5.1 and earlier, VMware ACE 2.5.1 and earlier, and VMware Server 1.0.x before 1.0.9 build 156507 and 2.0.x before 2.0.1 build 156745 uses the METHOD_NEITHER communication method for IOCTLs, which allows local users to cause a denial of service via a crafted IOCTL request.