A critical vulnerability in VMware Inc.s virtualization software for Windows lets attackers escape the “guest” operating system and modify or add files to the underlying “host” system. As of Sunday, there was no patch available for the flaw, which affects the Windows client virtualization programs, including Workstation, Player and ACE. The company’s virtual machines for Windows servers and for Mac- and Linux-based hosts are not at risk. A similar bug was reported by VeriSign Inc. to VMware in March 2007.”]