Guides

Ensure that default service accounts are not actively used. (RBAC)

The default service account should not be used to ensure that rights granted to applications can be more easily audited and reviewed. Kubernetes provides a default service account which is used by cluster workloads where no specific service account is assigned to the pod. Where access to the Kubernetes API from a pod is required, a specific service account should be created for that pod, and rights granted to that service account. The default service account should be configured such that it does not provide a service account token and does not have any explicit rights assignments.

Suggest Edits

Risk Level: Low
Cloud Entity: Kubernetes Role Binding
CloudGuard Rule ID: D9.K8S.IAM.36
Covered by Spectral: Yes
Category: Security, Identity, & Compliance

GSL LOGIC

KubernetesRoleBinding should not have subjects contain-any [ name='default' and kind='ServiceAccount' ]

REMEDIATION

Create explicit service accounts wherever a Kubernetes workload requires specific access to the Kubernetes API server. Modify the configuration of each default service account to include this value:
automountServiceAccountToken: false

References

  1. https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/
  2. https://aws.github.io/aws-eks-best-practices/iam/#disable-auto-mounting-ofservice-account-tokens (EKS)

Kubernetes Role Binding

A role binding grants the permissions defined in a role to a user or set of users. It holds a list of subjects (users, groups, or service accounts), and a reference to the role being granted. A RoleBinding grants permissions within a specific namespace whereas a ClusterRoleBinding grants that access cluster-wide.

Compliance Frameworks

  • CIS Amazon Elastic Kubernetes Service (EKS) Benchmark v1.0.1
  • CIS Amazon Elastic Kubernetes Service (EKS) Benchmark v1.1.0
  • CIS Amazon Elastic Kubernetes Service (EKS) Benchmark v1.2.0
  • CIS Amazon Elastic Kubernetes Service (EKS) Benchmark v1.3.0
  • CIS Google Kubernetes Engine (GKE) Benchmark v1.2.0
  • CIS Google Kubernetes Engine (GKE) Benchmark v1.4.0
  • CIS Kubernetes Benchmark v1.20
  • CIS Kubernetes Benchmark v1.23
  • CIS Kubernetes Benchmark v1.24
  • CIS Kubernetes Benchmark v1.5.1
  • CIS Kubernetes Benchmark v1.6.1
  • CIS Microsoft Kubernetes Engine (AKS) Benchmark v1.1.0
  • CIS Microsoft Kubernetes Engine (AKS) Benchmark v1.3.0
  • CIS OpenShift Container Platform v4 Benchmark v1.1.0
  • CIS OpenShift Container Platform v4 Benchmark v1.4.0
  • Kubernetes NIST.SP.800-190
  • Kubernetes v.1.13 CloudGuard Best Practices
  • Kubernetes v.1.14 CloudGuard Best Practices
  • OpenShift Container Platform v3

Updated about 1 year ago