Spyglass: demand-provisioned Linux containers for private network access
November 8, 2015
System administrators are required to access the privileged, or "super-user," interfaces of computing, networking, and storage resources they support. This low-level infrastructure underpins most of the security tools and features common today and is assumed to be secure. A malicious system administrator or malware on the system administrator's client system can silently subvert this computing infrastructure. In the case of cloud system administrators, unauthorized privileged access has the potential to cause grave damage to the cloud provider and their customers. In this paper, we describe Spyglass, a tool for managing, securing, and auditing administrator access to private or sensitive infrastructure networks by creating on-demand bastion hosts inside of Linux containers. These on-demand bastion containers differ from regular bastion hosts in that they are nonpersistent and last only for the duration of the administrator's access. Spyglass also captures command input and screen output of all administrator activities from outside the container, allowing monitoring of sensitive infrastructure and understanding of the actions of an adversary in the event of a compromise. Through our evaluation of Spyglass for remote network access, we show that it is more difficult to penetrate than existing solutions, does not introduce delays or major workflow changes, and increases the amount of tamper-resistant auditing information that is captured about a system administrator's access.