Cis Eks V160 4.1.6

4.1.6 Ensure that Service Account Tokens are only mounted where necessary (Automated)

Profile Applicability

• Level 1

Description

Service accounts tokens should not be mounted in pods except where the workload running in the pod explicitly needs to communicate with the API server.

Rationale

Mounting service account tokens inside pods can provide an avenue for privilege escalation attacks where an attacker is able to compromise a single pod in the cluster.

Avoiding mounting these tokens removes this attack avenue.

Impact

Pods mounted without service account tokens will not be able to communicate with the API server, except where the resource is available to unauthenticated principals.

Audit Procedure

Review pod and service account objects in the cluster and ensure that the option below is set, unless the resource explicitly requires this access.

automountServiceAccountToken: false

kubectl get pods --all-namespaces -o yaml | grep automountServiceAccountToken
kubectl get serviceaccounts --all-namespaces -o yaml | grep automountServiceAccountToken

Remediation

Regularly review pod and service account objects in the cluster to ensure that the automountServiceAccountToken setting is false for pods and accounts that do not explicitly require API server access.

automountServiceAccountToken: false

Default Value

By default, all pods get a service account token mounted in them.

References

1. https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/

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