Shuttle: Intrusion Recovery for PaaS

Abstract

The number of applications being deployed using the Platform as a Service (PaaS) cloud computing model is increasing. Despite the security controls implemented by cloud service providers, we expect intrusions to strike such applications. We present Shuttle, a novel intrusion recovery service. Shuttle recovers from intrusions in applications deployed in PaaS platforms. Our approach allows undoing changes to the state of PaaS applications due to intrusions, without loosing the effect of legitimate operations performed after the intrusions take place. We combine a record-and-replay approach with the elasticity provided by cloud offerings to recover applications deployed on various instances and backed by distributed databases. The service loads a database snapshot taken before the intrusion and replays subsequent requests, as much in parallel as possible, while continuing to execute incoming requests. We present an experimental evaluation of Shuttle on Amazon Web Services. We show Shuttle can replay 1 million requests in 10 minutes and that it can duplicate the number of requests replayed per second by increasing the number of application servers from 1 to 3.