---
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: "/bin/ps -fC $kubeletbin"
        audit_config: "/bin/cat $kubeletconf"
        tests:
          test_items:
            - flag: "--anonymous-auth"
              path: '{.authentication.anonymous.enabled}'
              set: true
              compare:
                op: eq
                value: false
        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: "/bin/ps -fC $kubeletbin"
        audit_config: "/bin/cat $kubeletconf"
        tests:
          test_items:
            - flag: --authorization-mode
              path: '{.authorization.mode}'
              set: true
              compare:
                op: nothave
                value: 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
        scored: true

      - id: 2.1.3
        text: Ensure that the --client-ca-file argument is set as appropriate (Scored)
        audit: "/bin/ps -fC $kubeletbin"
        audit_config: "/bin/cat $kubeletconf"
        tests:
          test_items:
            - flag: --client-ca-file
              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: "/bin/ps -fC $kubeletbin"
        audit_config: "/bin/cat $kubeletconf"
        tests:
          test_items:
            - flag: "--read-only-port"
              path: '{.readOnlyPort}'
              set: true
              compare:
                op: eq
                value: 0
        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: "/bin/ps -fC $kubeletbin"
        audit_config: "/bin/cat $kubeletconf"
        tests:
          test_items:
            - flag: --streaming-connection-idle-timeout
              path: '{.streamingConnectionIdleTimeout}'
              set: true
              compare:
                op: noteq
                value: 0
            - flag: --streaming-connection-idle-timeout
              path: '{.streamingConnectionIdleTimeout}'
              set: false
          bin_op: or
        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: "/bin/ps -fC $kubeletbin"
        audit_config: "/bin/cat $kubeletconf"
        tests:
          test_items:
            - flag: --protect-kernel-defaults
              path: '{.protectKernelDefaults}'
              set: true
              compare:
                op: eq
                value: 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: "/bin/ps -fC $kubeletbin"
        audit_config: "/bin/cat $kubeletconf"
        tests:
          test_items:
            - flag: --make-iptables-util-chains
              path: '{.makeIPTablesUtilChains}'
              set: true
              compare:
                op: eq
                value: true
            - flag: --make-iptables-util-chains
              path: '{.makeIPTablesUtilChains}'
              set: false
          bin_op: or
        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: "/bin/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: "/bin/ps -fC $kubeletbin"
        audit_config: "/bin/cat $kubeletconf"
        tests:
          test_items:
            - flag: --event-qps
              path: '{.eventRecordQPS}'
              set: true
              compare:
                op: eq
                value: 0
        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: "/bin/ps -fC $kubeletbin"
        audit_config: "/bin/cat $kubeletconf"
        tests:
          test_items:
            - flag: --tls-cert-file
              path: '{.tlsCertFile}'
              set: true
            - flag: --tls-private-key-file
              path: '{.tlsPrivateKeyFile}'
              set: true
          bin_op: and
        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: "/bin/ps -fC $kubeletbin "
        type: skip
        tests:
          test_items:
            - flag: --cadvisor-port
              set: true
              compare:
                op: eq
                value: 0
            - flag: --cadvisor-port
              set: false
          bin_op: or
        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: "/bin/ps -fC $kubeletbin"
        audit_config: "/bin/cat $kubeletconf"
        tests:
          test_items:
            - flag: --rotate-certificates
              path: '{.rotateCertificates}'
              set: true
              compare:
                op: eq
                value: true
            - flag: --rotate-certificates
              path: '{.rotateCertificates}'
              set: false
          bin_op: or
        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: "/bin/ps -fC $kubeletbin"
        audit_config: "/bin/cat $kubeletconf"
        tests:
          test_items:
            - flag: RotateKubeletServerCertificate
              path: '{.featureGates.RotateKubeletServerCertificate}'
              set: true
              compare:
                op: eq
                value: 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: "/bin/ps -fC $kubeletbin"
        audit_config: "/bin/cat $kubeletconf"
        tests:
          test_items:
            - flag: --tls-cipher-suites
              path: '{range .tlsCipherSuites[:]}{}{'',''}{end}'
              set: true
              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
        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 permissions=%a $kubeletkubeconfig; fi'' '
        tests:
          test_items:
            - flag: "permissions"
              set: true
              compare:
                op: bitmask
                value: "644"
        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
              set: true
              compare:
                op: eq
                value: root:root
        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 permissions=%a $kubeletsvc; fi'' '
        tests:
          test_items:
            - flag: "permissions"
              set: true
              compare:
                op: bitmask
                value: "644"
        remediation: |
          Run the below command (based on the file location on your system) on the each worker
          node. For example,
          chmod 644 $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 permissions=%a $proxykubeconfig; fi'' '
        tests:
          test_items:
            - flag: "permissions"
              set: true
              compare:
                op: bitmask
                value: "644"
        remediation: |
          Run the below command (based on the file location on your system) on the each worker
          node. For example,
          chmod 644 $proxykubeconfig
        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
        scored: true

      - id: 2.2.7
        text: Ensure that the certificate authorities file permissions are set to 644 or more restrictive (Scored)
        audit: "/bin/sh -c 'if test -e $kubeletcafile; then stat -c permissions=%a $kubeletcafile; fi'"
        tests:
          bin_op: or
          test_items:
            - flag: "permissions"
              compare:
                op: bitmask
                value: "644"
              set: true
        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 (Scored)
        audit: |
          CAFILE=$(ps -ef | grep kubelet | grep -v apiserver | grep -- --client-ca-file= | awk -F '--client-ca-file=' '{print $2}' | awk '{print $1}')
          if [[ -z $CAFILE ]]; then
            CAFILE=$kubeletcafile
          fi
          if test -e $CAFILE; then stat -c %U:%G $CAFILE; fi
        tests:
          test_items:
            - flag: root:root
              set: true
              compare:
                op: eq
                value: root:root
        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 identified 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 permissions=%a $kubeletconf; fi'' '
        tests:
          test_items:
            - flag: "permissions"
              set: true
              compare:
                op: bitmask
                value: "644"
        remediation: |
          Run the following command (using the config file location identified in the Audit step)
          chmod 644 $kubeletconf
        scored: true