Container Security: Issues, Challenges, and the Road Ahead

Containers emerged as a lightweight alternative to virtual machines (VMs) that offer better microservice architecture support. The value of the container market is expected to reach $2.7 billion in 2020 as compared to $762 million in 2016. Although they are considered the standardized method for microservices deployment, playing an important role in cloud computing emerging fields such as service meshes, market surveys show that container security is the main concern and adoption barrier for many companies. In this paper, we survey the literature on container security and solutions. We have derived four generalized use cases that should cover security requirements within the host-container threat landscape. The use cases include: (I) protecting a container from applications inside it, (II) inter-container protection, (III) protecting the host from containers, and (IV) protecting containers from a malicious or semi-honest host. We found that the first three use cases utilize a software-based solutions that mainly rely on Linux kernel features (e.g., namespaces, CGroups, capabilities, and seccomp) and Linux security modules (e.g., AppArmor). The last use case relies on hardware-based solutions such as trusted platform modules (TPMs) and trusted platform support (e.g., Intel SGX). We hope that our analysis will help researchers understand container security requirements and obtain a clearer picture of possible vulnerabilities and attacks. Finally, we highlight open research problems and future research directions that may spawn further research in this area.