---
controls:
version: 1.13
id: 2
text: "Worker Node Security Configuration"
type: "node"
groups:
- id: 2.1
  text: "Kubelet"
  checks:
  - id: 2.1.1
    text: "Ensure that the --anonymous-auth argument is set to false (Scored)"
    audit: "cat $kubeletconf"
    tests:
      test_items:
      - path: "{.authentication.anonymous.enabled}"
        compare:
          op: eq
          value: false
        set: true
    remediation: |
      If using a Kubelet config file, edit the file to set authentication: anonymous: enabled to
      false .
      If using executable arguments, edit the kubelet service file
      $kubeletsvc 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: 2.1.2
    text: "Ensure that the --authorization-mode argument is not set to AlwaysAllow (Scored)"
    audit: "cat $kubeletconf"
    tests:
      test_items:
      - path: "{.authorization.mode}"
        compare:
          op: nothave
          value: "AlwaysAllow"
        set: true
    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
    scored: true

  - id: 2.1.3
    text: "Ensure that the --client-ca-file argument is set as appropriate (Scored)"
    audit: "cat $kubeletconf"
    tests:
      test_items:
      - path: "{.authentication.x509.clientCAFile}"
        set: true
    remediation: |
      If using a Kubelet config file, edit the file to set authentication: x509: clientCAFile to
      the location of the client CA file.
      If using command line arguments, edit the kubelet service file
      $kubeletsvc 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: 2.1.4
    text: "Ensure that the --read-only-port argument is set to 0 (Scored)"
    audit: "cat $kubeletconf"
    tests:
      test_items:
      - path: "{.readOnlyPort}"
        compare:
          op: eq
          value: 0
        set: true
    remediation: |
      If using a Kubelet config file, edit the file to set readOnlyPort to 0 .
      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.
      --read-only-port=0
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service
    scored: true

  - id: 2.1.5
    text: "Ensure that the --streaming-connection-idle-timeout argument is not set to 0 (Scored)"
    audit: "cat $kubeletconf"
    tests:
      bin_op: or
      test_items:
      - path: "{.streamingConnectionIdleTimeout}"
        compare:
          op: noteq
          value: 0
        set: true
      - path: "{.streamingConnectionIdleTimeout}"
        set: false
    remediation: |
      If using a Kubelet config file, edit the file to set streamingConnectionIdleTimeout to a
      value other than 0.
      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.
      --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: 2.1.6
    text: "Ensure that the --protect-kernel-defaults argument is set to true (Scored)"
    audit: "cat $kubeletconf"
    tests:
      test_items:
      - path: "{.protectKernelDefaults}"
        compare:
          op: eq
          value: true
        set: 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
    scored: true

  - id: 2.1.7
    text: "Ensure that the --make-iptables-util-chains argument is set to true (Scored)"
    audit: "cat $kubeletconf"
    tests:
      bin_op: or
      test_items:
      - path: "{.makeIPTablesUtilChains}"
        compare:
          op: eq
          value: true
        set: true
      - path: "{.makeIPTablesUtilChains}"
        set: false
    remediation: |
      If using a Kubelet config file, edit the file to set makeIPTablesUtilChains: true .
      If using command line arguments, edit the kubelet service file
      $kubeletsvc 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: 2.1.8
    text: "Ensure that the --hostname-override argument is not set (Scored)"
    # This is one of those properties that can only be set as a command line argument. 
    # To check if the property is set as expected, we need to parse the kubelet command 
    # instead reading the Kubelet Configuration file.
    audit: "ps -fC $kubeletbin"
    tests:
      test_items:
      - flag: "--hostname-override"
        set: false
    remediation: |
      Edit the kubelet service file $kubeletsvc
      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: 2.1.9
    text: "Ensure that the --event-qps argument is set to 0 (Scored)"
    audit: "cat $kubeletconf"
    tests:
      test_items:
      - path: "{.eventRecordQPS}"
        compare:
          op: eq
          value: 0
        set: true
    remediation: |
      If using a Kubelet config file, edit the file to set eventRecordQPS: 0 .
      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.
      --event-qps=0
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service
    scored: true

  - id: 2.1.10
    text: "Ensure that the --tls-cert-file and --tls-private-key-file arguments are set as appropriate (Scored)"
    audit: "cat $kubeletconf"
    tests:
      bin_op: and
      test_items:
      - path: "{.tlsCertFile}"
        set: true
      - path: "{.tlsPrivateKeyFile}"
        set: true
    remediation: |
      If using a Kubelet config file, edit the file to set tlsCertFile to the location of the certificate
      file to use to identify this Kubelet, and tlsPrivateKeyFile to the location of the
      corresponding private key file.
      If using command line arguments, edit the kubelet service file
      $kubeletsvc 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>
      Based on your system, restart the kubelet service. For example:
      systemctl daemon-reload
      systemctl restart kubelet.service
    scored: true

  - id: 2.1.11
    text: "[DEPRECATED] Ensure that the --cadvisor-port argument is set to 0"
    # This is one of those properties that can only be set as a command line argument. 
    # To check if the property is set as expected, we need to parse the kubelet command 
    # instead reading the Kubelet Configuration file.
    audit: "ps -fC $kubeletbin"
    type: "skip"
    tests:
      bin_op: or
      test_items:
      - flag: "--cadvisor-port"
        compare:
          op: eq
          value: 0
        set: true
      - flag: "--cadvisor-port"
        set: false
    remediation: |
      Edit the kubelet service file $kubeletsvc
      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: false

  - id: 2.1.12
    text: "Ensure that the --rotate-certificates argument is not set to false (Scored)"
    audit: "cat $kubeletconf"
    tests:
      test_items:
      - path: "{.rotateCertificates}"
        compare:
          op: eq
          value: true
        set: true
    remediation: |
      If using a Kubelet config file, edit the file to add the line rotateCertificates: true.
      If using command line arguments, edit the kubelet service file $kubeletsvc 
      on each worker node and add --rotate-certificates=true argument to 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: 2.1.13
    text: "Ensure that the RotateKubeletServerCertificate argument is set to true (Scored)"
    audit: "cat $kubeletconf"
    tests:
      test_items:
      - path: "{.featureGates.RotateKubeletServerCertificate}"
        compare:
          op: eq
          value: true
        set: true
    remediation: |
      Edit the kubelet service file $kubeletsvc
      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: 2.1.14
    text: "Ensure that the Kubelet only makes use of Strong Cryptographic Ciphers (Not Scored)"
    audit: "cat $kubeletconf"
    tests:
      test_items:
      - path: "{range .tlsCipherSuites[:]}{}{','}{end}"
        compare:
          op: valid_elements
          value: "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_GCM_SHA256"
        set: true
    remediation: |
      If using a Kubelet config file, edit the file to set TLSCipherSuites: to TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_GCM_SHA256
      If using executable arguments, edit the kubelet service file $kubeletsvc on each worker node and set the below parameter.
      --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_GCM_SHA256
    scored: false

- 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 $kubeletkubeconfig; then stat -c %a $kubeletkubeconfig; 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 $kubeletkubeconfig
      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 $kubeletkubeconfig; then stat -c %U:%G $kubeletkubeconfig; 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 $kubeletkubeconfig
      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 $kubeletsvc; then stat -c %a $kubeletsvc; 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 $kubeletsvc
      scored: true

    - id: 2.2.4
      text: "Ensure that the kubelet service file ownership is set to root:root (Scored)"
      audit: "/bin/sh -c 'if test -e $kubeletsvc; then stat -c %U:%G $kubeletsvc; 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 $kubeletsvc
      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 $proxykubeconfig; then stat -c %a $proxykubeconfig; 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 $proxykubeconfig

        Note - This test reports "FAIL" if kube-proxy has been configured
        using a kubernetes configMap. Only under this situation, the "FAIL" can safely be ignored 
        as the kube-proxy does not expose the kubeconfig file to the worker node.
      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 $proxykubeconfig; then stat -c %U:%G $proxykubeconfig; 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 $proxykubeconfig
          
          Note - This test reports "FAIL" if kube-proxy has been configured
          using a kubernetes configMap. Only under this situation, the "FAIL" can safely be ignored 
          as the kube-proxy does not expose the kubeconfig file to the worker node.
      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: |
        [Manual test]
        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 (Scored)"
      audit: "/bin/sh -c 'if test -e $kubeletcafile; then stat -c %U:%G $kubeletcafile; fi'"
      tests:
        test_items:
          - flag: "root:root"
            compare:
              op: eq
              value: root:root
            set: true
      remediation: |
        Run the following command to modify the ownership of the --client-ca-file .
        chown root:root <filename>
      scored: true

    - id: 2.2.9
      text: "Ensure that the kubelet configuration 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 following command (using the config file location identied in the Audit step)
        chown root:root $kubeletconf
      scored: true

    - id: 2.2.10
      text: "Ensure that the kubelet configuration file has permissions 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 following command (using the config file location identied in the Audit step)
        chmod 644 $kubeletconf
      scored: true