kube-bench/cfg/1.8/node.yaml

---
controls:
version: 1.8
id: 2
text: "Worker Node Security Configuration"
type: "node"
groups:
- id: 2.1
  text: "Kubelet"
  checks:
  - id: 2.1.1
    text: "Ensure that the --allow-privileged argument is set to false (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "--allow-privileged"
        compare:
          op: eq
          value: false
        set: true
    remediation: |
      Edit the kubelet service file $kubeletconf
      on each worker node and set the below parameter in KUBELET_SYSTEM_PODS_ARGS variable.
      --allow-privileged=false
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

  - id: 2.1.2
    text: "Ensure that the --anonymous-auth argument is set to false (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "--anonymous-auth"
        compare:
          op: eq
          value: false
        set: true
    remediation: |
      Edit the kubelet service file $kubeletconf
      on each worker node and set the below parameter in KUBELET_SYSTEM_PODS_ARGS variable.
      --anonymous-auth=false
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

  - id: 2.1.3
    text: "Ensure that the --authorization-mode argument is not set to AlwaysAllow (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "--authorization-mode"
        compare:
          op: nothave
          value: "AlwaysAllow"
        set: true
    remediation: |
      Edit the kubelet service file $kubeletconf
      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      
    scored: true

  - id: 2.1.4
    text: "Ensure that the --client-ca-file argument is set as appropriate (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "--client-ca-file"
        set: true 
    remediation: |
      Edit the kubelet service file $kubeletconf
      on each worker node and set the below parameter in KUBELET_AUTHZ_ARGS variable.
      --client-ca-file=<path/to/client-ca-file>
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

  - id: 2.1.5
    text: "Ensure that the --read-only-port argument is set to 0 (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "--read-only-port"
        compare:
          op: eq
          value: 0
        set: true 
    remediation: |
      Edit the kubelet service file $kubeletconf
      on each worker node and set the below parameter in KUBELET_SYSTEM_PODS_ARGS variable.
      --read-only-port=0
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

  - id: 2.1.6
    text: "Ensure that the --streaming-connection-idle-timeout argument is not set to 0 (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "--streaming-connection-idle-timeout"
        compare:
          op: noteq
          value: 0
        set: true
    remediation: |
      Edit the kubelet service file $kubeletconf
      on each worker node and set the below parameter in KUBELET_SYSTEM_PODS_ARGS variable.
      --streaming-connection-idle-timeout=5m
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

  - id: 2.1.7
    text: "Ensure that the --protect-kernel-defaults argument is set to true (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "--protect-kernel-defaults"
        compare:
          op: eq
          value: true
        set: true
    remediation: |
      Edit the kubelet service file $kubeletconf
      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      
    scored: true

  - id: 2.1.8
    text: "Ensure that the --make-iptables-util-chains argument is set to true (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      bin_op: or
      test_items:
      - flag: "--make-iptables-util-chains"
        compare:
          op: eq
          value: true
        set: true
    remediation: |
      Edit the kubelet service file $kubeletconf
      on each worker node and remove the --make-iptables-util-chains argument from the
      KUBELET_SYSTEM_PODS_ARGS variable.
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

  - id: 2.1.9
    text: "Ensure that the --keep-terminated-pod-volumes argument is set to false (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "--keep-terminated-pod-volumes"
        compare:
          op: eq
          value: false
        set: true
    remediation: |
      Edit the kubelet service file $kubeletconf
      on each worker node and set the below parameter in KUBELET_SYSTEM_PODS_ARGS variable.
      --keep-terminated-pod-volumes=false
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

  - id: 2.1.10
    text: "Ensure that the --hostname-override argument is not set (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "--hostname-override"
        set: false
    remediation: |
      Edit the kubelet service file $kubeletconf
      on each worker node and remove the --hostname-override argument from the
      KUBELET_SYSTEM_PODS_ARGS variable.
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

  - id: 2.1.11
    text: "Ensure that the --event-qps argument is set to 0 (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "--event-qps"
        compare:
          op: eq
          value: 0
        set: true
    remediation: |
      Edit the kubelet service file $kubeletconf
      on each worker node and set the below parameter in KUBELET_SYSTEM_PODS_ARGS variable.
      --event-qps=0
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

  - id: 2.1.12
    text: "Ensure that the --tls-cert-file and --tls-private-key-file arguments are set as appropriate (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "--tls-cert-file"
        set: true
      - flag: "--tls-private-key-file"
        set: true
    remediation: |
      Follow the Kubernetes documentation and set up the TLS connection on the Kubelet.
      Then edit the kubelet service file /etc/systemd/system/kubelet.service.d/10-
      kubeadm.conf on each worker node and set the below parameters in
      KUBELET_CERTIFICATE_ARGS variable.
      --tls-cert-file=<path/to/tls-certificate-file>
      file=<path/to/tls-key-file>
      --tls-private-key-
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

  - id: 2.1.13
    text: "Ensure that the --cadvisor-port argument is set to 0 (Scored)"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "--cadvisor-port"
        compare:
          op: eq
          value: 0
        set: true
    remediation: |
      Edit the kubelet service file $kubeletconf
      on each worker node and set the below parameter in KUBELET_CADVISOR_ARGS variable.
      --cadvisor-port=0
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

  - id: 2.1.14
    text: "Ensure that the RotateKubeletClientCertificate argument is set to true"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "RotateKubeletClientCertificate"
        compare:
          op: eq
          value: true
        set: true
    remediation: |
      Edit the kubelet service file $kubeletconf
      on each worker node and remove the --feature-
      gates=RotateKubeletClientCertificate=false argument from the
      KUBELET_CERTIFICATE_ARGS variable.
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

  - id: 2.1.15
    text: "Ensure that the RotateKubeletServerCertificate argument is set to true"
    audit: "ps -ef | grep $kubeletbin | grep -v grep"
    tests:
      test_items:
      - flag: "RotateKubeletServerCertificate"
        compare:
          op: eq
          value: true
        set: true
    remediation: |
      Edit the kubelet service file $kubeletconf
      on each worker node and set the below parameter in KUBELET_CERTIFICATE_ARGS variable.
      --feature-gates=RotateKubeletServerCertificate=true
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service      
    scored: true

- id: 2.2
  text: "Configuration Files"
  checks:
    - id: 2.2.1
      text: "Ensure that the kubelet.conf file permissions are set to 644 or
      more restrictive (Scored)"
      audit: "/bin/sh -c 'if test -e $kubeletconf; then stat -c %a $kubeletconf; fi'"
      tests:
        bin_op: or
        test_items:
          - flag: "644"
            compare:
              op: eq
              value: "644"
            set: true
          - flag: "640"
            compare:
              op: eq
              value: "640"
            set: true
          - flag: "600"
            compare:
              op: eq
              value: "600"
            set: true
      remediation: |
        Run the below command (based on the file location on your system) on the each worker
        node. For example,
        chmod 644 $kubeletconf        
      scored: true

    - id: 2.2.2
      text: "Ensure that the kubelet.conf file ownership is set to root:root (Scored)"
      audit: "/bin/sh -c 'if test -e $kubeletconf; then stat -c %U:%G $kubeletconf; fi'"
      tests:
        test_items:
          - flag: "root:root"
            compare:
              op: eq
              value: root:root
            set: true
      remediation: |
        Run the below command (based on the file location on your system) on the each worker
        node. For example,
        chown root:root /etc/kubernetes/kubelet.conf        
      scored: true

    - id: 2.2.3
      text: "Ensure that the kubelet service file permissions are set to 644 or
      more restrictive (Scored)"
      audit: "/bin/sh -c 'if test -e $kubeletconf; then stat -c %a $kubeletconf; fi'"
      tests:
        bin_op: or
        test_items:
        - flag: "644"
          compare:
            op: eq
            value: 644
          set: true
        - flag: "640"
          compare:
            op: eq
            value: "640"
          set: true
        - flag: "600"
          compare:
            op: eq
            value: "600"
          set: true
      remediation: |
        Run the below command (based on the file location on your system) on the each worker
        node. For example,
        chmod 755 $kubeletconf        
      scored: true

    - id: 2.2.4
      text: "2.2.4 Ensure that the kubelet service file ownership is set to root:root (Scored)"
      audit: "/bin/sh -c 'if test -e $kubeletconf; then stat -c %U:%G $kubeletconf; fi'"
      tests:
        test_items:
        - flag: "root:root"
          set: true
      remediation: |
        Run the below command (based on the file location on your system) on the each worker
        node. For example,
        chown root:root $kubeletconf        
      scored: true

    - id: 2.2.5
      text: "Ensure that the proxy kubeconfig file permissions are set to 644 or more
      restrictive (Scored)"
      audit: "/bin/sh -c 'if test -e $proxyconf; then stat -c %a $proxyconf; fi'"
      tests:
        bin_op: or
        test_items:
        - flag: "644"
          compare:
            op: eq
            value: "644"
          set: true
        - flag: "640"
          compare:
            op: eq
            value: "640"
          set: true
        - flag: "600"
          compare:
            op: eq
            value: "600"
          set: true
      remediation: |
        Run the below command (based on the file location on your system) on the each worker
        node. For example,
        chmod 644 $proxyconf        
      scored: true

    - id: 2.2.6
      text: "Ensure that the proxy kubeconfig file ownership is set to root:root (Scored)"
      audit: "/bin/sh -c 'if test -e $proxyconf; then stat -c %U:%G $proxyconf; fi'"
      tests:
        test_items:
        - flag: "root:root"
          set: true
      remediation: |
          Run the below command (based on the file location on your system) on the each worker
          node. For example,
          chown root:root $proxyconf          
      scored: true

    - id: 2.2.7
      text: "Ensure that the certificate authorities file permissions are set to
      644 or more restrictive (Scored)"
      type: manual
      remediation: |
        Run the following command to modify the file permissions of the --client-ca-file
        chmod 644 <filename>        
      scored: true

    - id: 2.2.8
      text: "Ensure that the client certificate authorities file ownership is set to root:root"
      audit: "/bin/sh -c 'if test -e $ca-file; then stat -c %U:%G $ca-file; fi'"
      type: manual
      remediation: |
        Run the following command to modify the ownership of the --client-ca-file .
        chown root:root <filename>        
      scored: true