Server and PC virtualization juggernaut VMware has issued a patch for the Workstation hypervisor that plugs a privilege-escalation hole on machines that use Linux as the host environment for the hypervisor.

Machines that use Windows as a host environment for the Workstation hypervisor are not affected by the local privilege-escalation vulnerability, according to VMware's security advisory, issued on Tuesday.

The security hole applies to VMware Workstation 7.1.3 and 6.5.5, and the related vmrun utility. The vmrun utility is a command-line tool to control virtual machines and to automate the operations of those VMs through scripts. An associated set of code called the VIX APIs load on machines to allow script control of virtual machines.

On machines using Linux, the VIX API for Linux 1.10.2 libraries are automatically loaded, and allow for C, Perl, Visual Basic, VBscript, and C# to be used to control VMs running on hypervisors, the hypervisors themselves, and the vCenter console that controls the server versions of VMware's virtualization tools.

The vmrun utility and the VIX API libraries are installed by default with Workstation hypervisors, and this is where the escalation issue is a problem on machines that use Linux hosts to support the hypervisor, which in turn can support Windows, Linux, and other kinds of guests inside of VMs. VMware was not entirely clear about what the problem is.

"In non-standard filesystem configurations, an attacker with the ability to place files into a predefined library path, could take execution control of vmrun," the company said in the security advisory.

VMware has issued a patch for Workstation 7.1.4, which is in build 385536 or later, and has created an updated version of the vmrun tool for Workstation 6.5.X. A patch for the VIX API 1.X releases is still pending. ®