Ensure that the --bind-address argument is set to 127.0.0.1 (Scheduler)

Do not bind the scheduler service to non-loopback insecure addresses. The Scheduler API service which runs on port 10251/TCP by default is used for health and metrics information and is available without authentication or encryption. As such it should only be bound to a localhost interface, to minimize the cluster's attack surface

Risk Level: High
Cloud Entity: Pods
CloudGuard Rule ID: D9.K8S.NET.21
Covered by Spectral: Yes
Category: Compute

GSL LOGIC

KubernetesPod where labels contain [value='kube-scheduler'] and namespace = 'kube-system' should have spec.containers with [(parsedArgs contain [key like 'bind-address' and value = '127.0.0.1']) or (parsedArgs contain-none [key like 'bind-address'])]

REMEDIATION

Edit the Scheduler pod specification file /etc/kubernetes/manifests/kube-scheduler.yaml on the master node and ensure the correct value for the --bind-address parameter

References

  1. https://kubernetes.io/docs/reference/command-line-tools-reference/kube-scheduler/

Pods

Pods are the smallest deployable units of computing that can be created and managed in Kubernetes.A Pod is a group of one or more containers (such as Docker containers), with shared storage/network, and a specification for how to run the containers.

Compliance Frameworks

  • 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
  • Kubernetes NIST.SP.800-190
  • Kubernetes v.1.13 CloudGuard Best Practices
  • Kubernetes v.1.14 CloudGuard Best Practices