Enforcing virtualized systems security

• Main Author: Benzina, Hedi
• Language: ENG
• Published: École normale supérieure de Cachan - ENS Cachan 2012
• Subjects: [INFO:INFO_OH] Computer Science/Other; [INFO:INFO_OH] Informatique/Autre; Sécurity; Virtualization; Security policies; Intrusion detection; Formal languages; Temporal languages
• Online Access: http://tel.archives-ouvertes.fr/tel-00846513; http://tel.archives-ouvertes.fr/docs/00/84/65/13/PDF/Benzina2012.pdf

Virtual machine technology is rapidly gaining acceptance as a fundamental building block in enterprise data centers. It is most known for improving efficiency and ease of management. However, the central issue of this technology is security. We propose in this thesis to enforce the security of virtualized systems and introduce new approaches that deal with different security aspects related not only to the technology itself but also to its deployment and maintenance. We first propose a new architecture that offers real-time supervision of a complete virtualized architecture. The idea is to implement decentralized supervision on one single physical host. We study the advantages and the limits of this architecture and show that it is unable to react according to some new stealthy attacks. As a remedy, we introduce a new procedure that permits to secure the sensitive resources of a virtualized system and make sure that families of attacks can not be run at all. We introduce a variant of the LTL language with new past operators and show how policies written in this language can be easily translated to attack signatures that we use to detect attacks on the system. We also analyse the impact that an insecure network communication between virtual machines can have on the global security of the virtualized system. We propose a multilevel security policy model that covers almost all the network operations that can be performed by a virtual machine. We also deal with some management operations and introduce the related constraints that must be satisfied when an operation is performed.