A "very serious" security vulnerability has been discovered in VMware's line of virtual computing products, including VMware Workstation, GSX Server, ACE and VMware Player. The flaw could enable malware to effectively "jump" from the virtual machine onto the real computer running VMware software.

"Since VMware is used heavily in malware research, this is an obvious danger," says Alex Eckelberry, CEO of Sunbelt Software. VMware has posted updates to the affected products, which customers are urged to download immediately. Alternatively, users can disable the NAT service, which contains the vulnerability.