The bug allows a guest operating system (that’s the OS running inside the virtual machine) to execute code on the host operating system (the OS running the actual virtualization program). Kostya created a short video that shows just how this works. In the video, a Windows XP guest operating system launches the Calculator application in Vista, the host operating system.
The fix is simple… VMWare has already done the patch. Just go to http://www.vmware.com/mac and upgrade to version 2.0.4.