A First Look at Power Attacks in Multi-Tenant Data Centers

Oversubscription increases the utilization of expensive power infrastructure in multi-tenant data centers, but it can create dangerous emergencies and outages if the designed power capacity is exceeded. Despite the safeguards in place today to prevent power outages, this extended abstract demonstrates that multi-tenant data centers are vulnerable to well-timed power attacks launched by a malicious tenant (i.e., attacker). Further, we show that there is a physical side channel -- a thermal side channel due to hot air recirculation -- that contains information about the benign tenants' runtime power usage. We develop a state-augmented Kalman filter that guides an attacker to precisely time its power attacks at moments that coincide with the benign tenants' high power demand, thus overloading the designed power capacity. Our experimental results show that an attacker can capture 53% of all attack opportunities, significantly compromising the data center availability.