Guides

Ensure that the --protect-kernel-defaults argument is set to true (Kubelet)

Protect tuned kernel parameters from overriding kubelet default kernel parameter values. Kernel parameters are usually tuned and hardened by the system administrators before putting the systems into production. These parameters protect the kernel and the system. Your kubelet kernel defaults that rely on such parameters should be appropriately set to match the desired secured system state. Ignoring this could potentially lead to running pods with undesired kernel behavior.

Suggest Edits

Risk Level: High
Cloud Entity: Node
CloudGuard Rule ID: D9.K8S.OPE.01
Covered by Spectral: Yes
Category: Compute

GSL LOGIC

KubernetesNode where not kubeletData isEmpty() should have kubeletData.kubeletconfig.protectKernelDefaults = 'true'

REMEDIATION

  • If using a Kubelet config file, edit the file to set protectKernelDefaults: true.

  • If using command line arguments, edit the kubelet service file
    $kubeletsvc on each worker node and
    set the below parameter in KUBELET_SYSTEM_PODS_ARGS variable.
    --protect-kernel-defaults=true
    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
    protectKernelDefaults 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/

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 Google Kubernetes Engine (GKE) Benchmark v1.2.0
  • 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 OpenShift Container Platform v4 Benchmark v1.1.0
  • Kubernetes NIST.SP.800-190
  • Kubernetes v.1.13 CloudGuard Best Practices
  • Kubernetes v.1.14 CloudGuard Best Practices
  • OpenShift Container Platform v3

Updated over 1 year ago