OnApp before 5.0.0-88, 5.5.0-93, and 6.0.0-196 allows an attacker to run arbitrary commands with root privileges on servers managed by OnApp for XEN/KVM hypervisors. To exploit the vulnerability an attacker has to have control of a single server on a given cloud (e.g. by renting one). From the source server, the attacker can craft any command and trigger the OnApp platform to execute that command with root privileges on a target server.