A Measurement Study on Co-residence Threat inside the Cloud

As the most basic cloud service model, Infrastructure as a Service (IaaS) has been widely used for serving the ever-growing computing demand due to the prevalence of the cloud. Using pools of hypervisors within the cloud, IaaS can support a large number of Virtual Machines (VMs) and scale services in a highly dynamic manner. However, it is well-known that the VMs in IaaS are vulnerable to co-residence threat, which can be easily exploited to launch different malicious attacks. In this measurement study, we investigate how IaaS evolves in VM placement, network management, and Virtual Private Cloud (VPC), as well as the impact upon co-residence. Specifically, through intensive measurement probing, we first profile the dynamic environment of cloud instances inside the cloud. Then using real experiments, we quantify the impacts of VM placement and network management upon co-residence. Moreover, we explore VPC, which is a defensive network-based service of Amazon EC2 for security enhancement, from the routing perspective. On one hand, our measurement shows that VPC is widely used and can indeed suppress co-residence threat. On the other hand, we demonstrate a new approach to achieving co-residence in VPC, indicating that co-residence threat still exists in the cloud.