In this talk, we present the first practical cache covert channel in the cloud. The goal is to secretly exfiltrate sensitive data from one fully isolated virtual machine to another virtual machine on the same physical host. Both communication endpoints require no privileges and run as regular user programs.
by Michael Schwarz, Manuel Weber
Full Abstract: https://www.blackhat.com/asia-17/briefings/schedule/index.html#hello-from-the-other-side-ssh-over-robust-cache-covert-channels-in-the-cloud-5376