  Virtualization technology is nowadays adopted in security-critical embedded
systems to achieve higher performance and more design flexibility. However, it
also comes with new security threats, where attackers leverage timing covert
channels to exfiltrate sensitive information from a partition using a trojan.
  This paper presents a novel approach for the experimental assessment of
timing covert channels in embedded hypervisors, with a case study on security
assessment of a commercial hypervisor product (Wind River VxWorks MILS), in
cooperation with a licensed laboratory for the Common Criteria security
certification. Our experimental analysis shows that it is indeed possible to
establish a timing covert channel, and that the approach is useful for system
designers for assessing that their configuration is robust against this kind of
information leakage.
