Abstract
As today's cloud providers strive to attract customers with better services and less downtime in a highly competitive market, they increasingly rely on remote administrators including those from third party providers for fulfilling regular maintenance tasks. In such a scenario, the privileges granted for remote administrators to complete their assigned tasks may allow an attacker with stolen credentials of an administrator, or a dishonest remote administrator, to pose severe insider threats to both the cloud tenants and provider. In this paper, we take the first step towards understanding and mitigating such a threat. Specifically, we model the maintenance task assignments and their corresponding security impact due to privilege escalation. We then mitigate such impact through optimizing the task assignments with respect to given constraints. The simulation results demonstrate the effectiveness of our solution in various situations.