Risks

CNIs (Container Network Interfaces) enable the virtual networking that connects containers across multiple host VMs. However, not all CNIs provide encrypted communication, which poses significant risks to data security within a Kubernetes cluster. When communication between containers is unencrypted, it becomes vulnerable to eavesdropping, data tampering, and unauthorized access.

Unencrypted CNIs leave the network open to various attack vectors, including the risk of eavesdropping on sensitive data and integrity issues where data in transit can be altered. Additionally, Network Policies may be ignored by CNIs that do not support encrypted communication, further increasing the risk of unauthorized access and lateral movement within the cluster.

To mitigate these risks, using CNIs that offer encryption and ensuring that it is activated is critical.