Exploring Virtual Machine Covert Channel via I/O Performance Interference

The weakness of performance isolation in system virtualization leaks a time window for various kinds of attacks which can be leveraged by malicious users to threaten the security of the virtual machines (VMs) atop or construct hidden information channel. In this paper, we propose vLeaker, a practical covert timing channel built on fine-grained VM I/O performance interference, by which VMs co-resident in storage aspect can exchange the information with relatively high transmission speed and low data error rate. We evaluate our vLeaker system on Xen and VMware hypervisor and show that the maximal transmission rate can arrive at 125 bps on our local test bed. Moreover, the effective transmission rate ranges from 72 to 124 bps with average error rate lower than 13% under different configurations.