Guides

Ensure that the --authorization-mode argument is not set to AlwaysAllow (Kubelet)

Do not allow all requests. Enable explicit authorization. Kubelets, by default, allow all authenticated requests (even anonymous ones) without needing explicit authorization checks from the apiserver. You should restrict this behavior and only allow explicitly authorized requests.

Suggest Edits

Risk Level: Critical
Cloud Entity: Node
CloudGuard Rule ID: D9.K8S.IAM.03
Covered by Spectral: Yes
Category: Compute

GSL LOGIC

KubernetesNode should have kubeletData.kubeletconfig.authorization.mode unlike '%AlwaysAllow%'

REMEDIATION

  • If using a Kubelet config file, edit the file to set authorization: mode to Webhook.

  • If using executable arguments, edit the kubelet service file
    $kubeletsvc on each worker node and
    set the below parameter in KUBELET_AUTHZ_ARGS variable.
    --authorization-mode=Webhook
    Based on your system, restart the kubelet service. For example:
    systemctl daemon-reload
    systemctl restart kubelet.service

  • If using the api configz endpoint consider searching for the status of authorization mode
    'Webhook' by extracting the live configuration from the nodes running kubelet.
    **See detailed step-by-step configmap procedures in
    https://kubernetes.io/docs/tasks/administer-cluster/reconfigure-kubelet/

References

  1. https://kubernetes.io/docs/admin/kubelet/
  2. https://kubernetes.io/docs/admin/kubelet-authentication-authorization/#kubelet-authentication

Node

A node is a worker machine in Kubernetes, previously known as a minion. A node may be a VM or physical machine, depending on the cluster. Each node contains the services necessary to run pods and is managed by the master components. The services on a node include the container runtime, kubelet and kube-proxy.

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 v1.4.0
  • CIS Kubernetes Benchmark v1.5.1
  • CIS Kubernetes Benchmark v1.6.1
  • 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