5.3.2 Ensure that all Namespaces have Network Policies defined - Namespaces

Information

Use network policies to isolate traffic in your cluster network.

Rationale:

Running different applications on the same Kubernetes cluster creates a risk of one compromised application attacking a neighboring application. Network segmentation is important to ensure that containers can communicate only with those they are supposed to. A network policy is a specification of how selections of pods are allowed to communicate with each other and other network endpoints.

Once there is any Network Policy in a namespace selecting a particular pod, that pod will reject any connections that are not allowed by any Network Policy. Other pods in the namespace that are not selected by any Network Policy will continue to accept all traffic

Impact:

Once there is any Network Policy in a namespace selecting a particular pod, that pod will reject any connections that are not allowed by any Network Policy. Other pods in the namespace that are not selected by any Network Policy will continue to accept all traffic'

Solution

Follow the documentation and create NetworkPolicy objects as you need them.

Default Value:

By default, all Pods in a project are accessible from other Pods and network endpoints; network policies are not created.

See Also

https://workbench.cisecurity.org/files/4260