It is the most widely used Linux on the top 1000 websites by traffic, the reference platform for OpenStack deployments, the most popular guestOS on public clouds, and ships on PCs from Dell, Lenovo, HP and other brands.
The flaw, which affected the virtual machine monitor (VMM) in Virtual PC, could enable an attacker to use applications running in user-space on a guestOS to access portions of the Virtual PC memory that should be inaccessible to those applications.
The software treats various versions of Windows as "guest" operating systems that are run on virtual machines launched within the Mac OS operating environment.