In computer security, virtual machine escape (VM escape) is the process of a program breaking out of the virtual machine (VM) on which it is running and interacting with the host operating system. In theory, a virtual machine is a "completely isolated guest operating system installation within a normal host operating system", but this is not always the case in practice.
For example, in 2008, a vulnerability (CVE-2008-0923) in VMware discovered by Core Security Technologies made VM escape possible on VMware Workstation 6.0.2 and 5.5.4. A fully working exploit labeled Cloudburst was developed by Immunity Inc. for Immunity CANVAS (a commercial penetration testing tool). Cloudburst was presented at Black Hat USA 2009.