From Virtualization Security Issues to Cloud Protection Opportunities: An In-Depth Analysis of System Virtualization Models

Abstract Virtualization methods and techniques play an important role in the development of cloud infrastructures and their services. They enable the decoupling of virtualized resources from the underlying hardware, and facilitate their sharing amongst multiple users. They contribute to the building of elaborated cloud services that are based on the instantiation and composition of these resources. Different models may support such a virtualization, including virtualization based on type-I and type-II hypervisors, OS-level virtualization, and unikernel virtualization. These virtualization models pose a large variety of security issues, but also offer new opportunities for the protection of cloud services. In this article, we describe and compare these virtualization models, in order to establish a reference architecture of cloud infrastructure. We then analyze the security issues related to these models from the reference architecture, by considering related vulnerabilities and attacks. Finally, we point out different recommendations with respect to the exploitation of these models for supporting cloud protection.