Zero Trust Container Architecture (ZTCA): A Framework for Applying Zero Trust Principals to Docker Containers

Containerisation is quickly becoming an accepted industry standard for development environments and Gartner, in a recent market forecast, estimated that by 2022 more than 75% of organisations will be using containers in production deployments. With this explosion in growth comes an added focus on security and best practices for using containers. The use of containers, in particular Docker containers, has altered some of the more traditional deployment paradigms by giving control of deployments to the development teams. This has massively benefited the DevOps release cycle, but at the expense of many mature security and review processes that are integrated into traditional deployments. Like all systems, containers need frameworks to guide best practices for deployments and to ensure mistakes are not made that increase the risk level or attack surface of an application or service using containers, or the containers themselves. Indeed, according to a recent presentation during DevSecCon24 by Justin Cormack, Security Lead at Docker Inc., Cormack believes most security issues related to Docker are due to misconfiguration rather than direct exploit. While work has been previously conducted with regards to container security and separately applying Zero Trust Networking Architecture to containers, in this work we will investigate the security state of a default deployment of the Docker container engine on Linux and analyse how the principals of Zero Trust Architecture can be extended beyond the domain of networking, distilled into a "Zero Trust Containers Architecture" and applied to secure Docker deployments. In order to determine this, research was conducted into the current state of Docker security and Zero Trust Architecture. Practical and theoretical attacks were reviewed against a default Docker deployment to identify common themes and areas of issue. Results were used to advise a generalised trust-based framework which was then used to analyse a Docker deployment and validate mitigation of a selection of the identified attacks, proving out the concept of the proposed "Zero Trust Container Architecture" framework.