https://www.cisa.gov/uscert/ncas/current-activity/2022/03/15/updated-kubernetes-hardening-guide
The National Security Agency (NSA) and CISA have updated their joint Cybersecurity Technical Report (CTR): Kubernetes Hardening Guide, originally released in August 2021, based on valuable feedback and inputs from the cybersecurity community.
Kubernetes is an open-source system that automates deployment, scaling, and management of applications run in containers. A container is a runtime environment that contains a software package and its dependencies. Kubernetes is often hosted in a cloud environment. The CTR provides recommended configuration and hardening guidance for setting up and securing a Kubernetes cluster.
CISA encourages users and administrators to review the updated Kubernetes Hardening Guide—which includes additional detail and explanations—and apply the hardening measures and mitigations to manage associated risks.