Risks

In a Kubernetes environment using Calico CNI, containers can communicate at the node level without restrictions. This lack of control over node-level communication exposes the cluster to several security risks, including bypassing security measures like Network Policies and increasing the chances of unauthorized access.

Risks of Unrestricted Node-Level Communication

Unencrypted communication at the node level means that attackers who compromise a container can bypass Network Policies by using the node’s networking stack. This can result in unauthorized access to other containers or node-level services, leading to lateral movement and potential privilege escalation.

To mitigate these risks, configuring Calico policies appropriately at the cluster level and ensuring encryption are essential steps.