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.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.