CIS 1.24 Self Assessment Guide

Overview

This document is a companion to the K3s security hardening guide. The hardening guide provides prescriptive guidance for hardening a production installation of K3s, and this benchmark guide is meant to help you evaluate the level of security of the hardened cluster against each control in the CIS Kubernetes Benchmark. It is to be used by K3s operators, security teams, auditors, and decision-makers.

This guide is specific to the v1.24 release line of K3s and the v1.24 release of the CIS Kubernetes Benchmark.

For more information about each control, including detailed descriptions and remediations for failing tests, you can refer to the corresponding section of the CIS Kubernetes Benchmark v1.6. You can download the benchmark, after creating a free account, in Center for Internet Security (CIS).

Testing controls methodology

Each control in the CIS Kubernetes Benchmark was evaluated against a K3s cluster that was configured according to the accompanying hardening guide.

Where control audits differ from the original CIS benchmark, the audit commands specific to K3s are provided for testing.

These are the possible results for each control:

• Pass - The K3s cluster under test passed the audit outlined in the benchmark.
• Not Applicable - The control is not applicable to K3s because of how it is designed to operate. The remediation section will explain why this is so.
• Warn - The control is manual in the CIS benchmark and it depends on the cluster's use case or some other factor that must be determined by the cluster operator. These controls have been evaluated to ensure K3s does not prevent their implementation, but no further configuration or auditing of the cluster under test has been performed.

This guide makes the assumption that K3s is running as a Systemd unit. Your installation may vary and will require you to adjust the "audit" commands to fit your scenario.

note

Only scored test, also know as automated tests are covered in this guide.

1.1 Control Plane Node Configuration Files

1.1.1 Ensure that the API server pod specification file permissions are set to 644 or more restrictive (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chmod 644 /etc/kubernetes/manifests/kube-apiserver.yaml

1.1.2 Ensure that the API server pod specification file ownership is set to root:root (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root /etc/kubernetes/manifests/kube-apiserver.yaml

1.1.3 Ensure that the controller manager pod specification file permissions are set to 600 or more restrictive (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 /etc/kubernetes/manifests/kube-controller-manager.yaml

1.1.4 Ensure that the controller manager pod specification file ownership is set to root:root (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root /etc/kubernetes/manifests/kube-controller-manager.yaml

1.1.5 Ensure that the scheduler pod specification file permissions are set to 600 or more restrictive (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 /etc/kubernetes/manifests/kube-scheduler.yaml

1.1.6 Ensure that the scheduler pod specification file ownership is set to root:root (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root /etc/kubernetes/manifests/kube-scheduler.yaml

1.1.7 Ensure that the etcd pod specification file permissions are set to 600 or more restrictive (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 /var/lib/rancher/k3s/server/db/etcd/config

1.1.8 Ensure that the etcd pod specification file ownership is set to root:root (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root /var/lib/rancher/k3s/server/db/etcd/config

1.1.9 Ensure that the Container Network Interface file permissions are set to 600 or more restrictive (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 <path/to/cni/files>

1.1.10 Ensure that the Container Network Interface file ownership is set to root:root (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chown root:root <path/to/cni/files>

1.1.11 Ensure that the etcd data directory permissions are set to 700 or more restrictive (Automated)

Result: PASS

Audit:

stat -c %a /var/lib/rancher/k3s/server/db/etcd

Expected Result: '700' is equal to '700'

Returned Value:

700

1.1.12 Ensure that the etcd data directory ownership is set to etcd:etcd (Automated)

Result: Not Applicable

Remediation: On the etcd server node, get the etcd data directory, passed as an argument --data-dir, from the command 'ps -ef | grep etcd'. Run the below command (based on the etcd data directory found above). For example, chown etcd:etcd /var/lib/etcd

1.1.13 Ensure that the admin.conf file permissions are set to 600 or more restrictive (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chmod 600 /var/lib/rancher/k3s/server/cred/admin.kubeconfig

1.1.14 Ensure that the admin.conf file ownership is set to root:root (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/k3s/server/cred/admin.kubeconfig; then stat -c %U:%G /var/lib/rancher/k3s/server/cred/admin.kubeconfig; fi'

Expected Result: 'root:root' is equal to 'root:root'

Returned Value:

root:root

1.1.15 Ensure that the scheduler.conf file permissions are set to 600 or more restrictive (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/k3s/server/cred/scheduler.kubeconfig; then stat -c permissions=%a /var/lib/rancher/k3s/server/cred/scheduler.kubeconfig; fi'

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600

1.1.16 Ensure that the scheduler.conf file ownership is set to root:root (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/k3s/server/cred/scheduler.kubeconfig; then stat -c %U:%G /var/lib/rancher/k3s/server/cred/scheduler.kubeconfig; fi'

Expected Result: 'root:root' is present

Returned Value:

root:root

1.1.17 Ensure that the controller-manager.conf file permissions are set to 600 or more restrictive (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/k3s/server/cred/controller.kubeconfig; then stat -c permissions=%a /var/lib/rancher/k3s/server/cred/controller.kubeconfig; fi'

Expected Result: permissions has permissions 600, expected 600 or more restrictive

Returned Value:

permissions=600

1.1.18 Ensure that the controller-manager.conf file ownership is set to root:root (Automated)

Result: PASS

Audit:

stat -c %U:%G /var/lib/rancher/k3s/server/tls

Expected Result: 'root:root' is equal to 'root:root'

Returned Value:

root:root

1.1.19 Ensure that the Kubernetes PKI directory and file ownership is set to root:root (Automated)

Result: PASS

Audit:

find /var/lib/rancher/k3s/server/tls | xargs stat -c %U:%G

Expected Result: 'root:root' is present

Returned Value:

root:root

1.1.20 Ensure that the Kubernetes PKI certificate file permissions are set to 600 or more restrictive (Automated)

Result: WARN

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chmod -R 600 /etc/kubernetes/pki/*.crt

1.1.21 Ensure that the Kubernetes PKI key file permissions are set to 600 (Automated)

Result: WARN

Remediation: Run the below command (based on the file location on your system) on the control plane node. For example, chmod -R 600 /etc/kubernetes/pki/*.key

1.2 API Server

1.2.1 Ensure that the --anonymous-auth argument is set to false (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'anonymous-auth'

Expected Result: '--anonymous-auth' is equal to 'false'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.2 Ensure that the --token-auth-file parameter is not set (Automated)

Result: PASS

Audit:

/bin/ps -ef | grep containerd | grep -v grep

Expected Result: '--token-auth-file' is not present

Returned Value:

root        2335    2318  0 18:38 ?        00:00:00 containerd -c /var/lib/rancher/k3s/agent/etc/containerd/config.toml -a /run/k3s/containerd/containerd.sock --state /run/k3s/containerd --root /var/lib/rancher/k3s/agent/containerd

1.2.3 Ensure that the --DenyServiceExternalIPs is not set (Automated)

Result: PASS

Audit:

/bin/ps -ef | grep containerd | grep -v grep

Expected Result: '--enable-admission-plugins' is present OR '--enable-admission-plugins' is not present

Returned Value:

root        2335    2318  0 18:38 ?        00:00:00 containerd -c /var/lib/rancher/k3s/agent/etc/containerd/config.toml -a /run/k3s/containerd/containerd.sock --state /run/k3s/containerd --root /var/lib/rancher/k3s/agent/containerd

1.2.4 Ensure that the --kubelet-https argument is set to true (Automated)

Result: Not Applicable

Remediation: Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the control plane node and remove the --kubelet-https parameter.

1.2.5 Ensure that the --kubelet-client-certificate and --kubelet-client-key arguments are set as appropriate (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'kubelet-certificate-authority'

Expected Result: '--kubelet-client-certificate' is present AND '--kubelet-client-key' is present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.6 Ensure that the --kubelet-certificate-authority argument is set as appropriate (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'kubelet-certificate-authority'

Expected Result: '--kubelet-certificate-authority' is present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.7 Ensure that the --authorization-mode argument is not set to AlwaysAllow (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'authorization-mode'

Expected Result: '--authorization-mode' does not have 'AlwaysAllow'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.8 Ensure that the --authorization-mode argument includes Node (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'authorization-mode'

Expected Result: '--authorization-mode' has 'Node'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.9 Ensure that the --authorization-mode argument includes RBAC (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'authorization-mode'

Expected Result: '--authorization-mode' has 'RBAC'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.10 Ensure that the admission control plugin EventRateLimit is set (Automated)

Result: WARN

Remediation: Follow the Kubernetes documentation and set the desired limits in a configuration file. Then, edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml and set the below parameters. --enable-admission-plugins=...,EventRateLimit,... --admission-control-config-file=<path/to/configuration/file>

1.2.11 Ensure that the admission control plugin AlwaysAdmit is not set (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'enable-admission-plugins'

Expected Result: '--enable-admission-plugins' does not have 'AlwaysAdmit' OR '--enable-admission-plugins' is not present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.12 Ensure that the admission control plugin AlwaysPullImages is set (Automated)

Result: WARN

Remediation: Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the control plane node and set the --enable-admission-plugins parameter to include AlwaysPullImages. --enable-admission-plugins=...,AlwaysPullImages,...

1.2.13 Ensure that the admission control plugin SecurityContextDeny is set if PodSecurityPolicy is not used (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'enable-admission-plugins'

Expected Result: '--enable-admission-plugins' has 'SecurityContextDeny' OR '--enable-admission-plugins' has 'PodSecurityPolicy'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.14 Ensure that the admission control plugin ServiceAccount is set (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep -v grep

Expected Result: '--disable-admission-plugins' is present OR '--disable-admission-plugins' is not present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.15 Ensure that the admission control plugin NamespaceLifecycle is set (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep -v grep

Expected Result: '--disable-admission-plugins' is present OR '--disable-admission-plugins' is not present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.16 Ensure that the admission control plugin NodeRestriction is set (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'enable-admission-plugins'

Expected Result: '--enable-admission-plugins' has 'NodeRestriction'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.17 Ensure that the --secure-port argument is not set to 0 (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'secure-port'

Expected Result: '--secure-port' is greater than 0 OR '--secure-port' is not present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.18 Ensure that the --profiling argument is set to false (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'profiling'

Expected Result: '--profiling' is equal to 'false'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.19 Ensure that the --audit-log-path argument is set (Automated)

Result: Not Applicable

Remediation: Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the control plane node and set the --audit-log-path parameter to a suitable path and file where you would like audit logs to be written, for example, --audit-log-path=/var/log/apiserver/audit.log

1.2.20 Ensure that the --audit-log-maxage argument is set to 30 or as appropriate (Automated)

Result: Not Applicable

Remediation: Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the control plane node and set the --audit-log-maxage parameter to 30 or as an appropriate number of days, for example, --audit-log-maxage=30

1.2.21 Ensure that the --audit-log-maxbackup argument is set to 10 or as appropriate (Automated)

Result: Not Applicable

Remediation: Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the control plane node and set the --audit-log-maxbackup parameter to 10 or to an appropriate value. For example, --audit-log-maxbackup=10

1.2.22 Ensure that the --audit-log-maxsize argument is set to 100 or as appropriate (Automated)

Result: Not Applicable

Remediation: Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the control plane node and set the --audit-log-maxsize parameter to an appropriate size in MB. For example, to set it as 100 MB, --audit-log-maxsize=100

1.2.23 Ensure that the --request-timeout argument is set as appropriate (Automated)

Result: Not Applicable

Remediation: Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml and set the below parameter as appropriate and if needed. For example, --request-timeout=300s

1.2.24 Ensure that the --service-account-lookup argument is set to true (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep -v grep

Expected Result: '--service-account-lookup' is not present OR '--service-account-lookup' is equal to 'true'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.25 Ensure that the --service-account-key-file argument is set as appropriate (Automated)

Result: Not Applicable

Remediation: Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the control plane node and set the --service-account-key-file parameter to the public key file for service accounts. For example, --service-account-key-file=<filename>

1.2.26 Ensure that the --etcd-certfile and --etcd-keyfile arguments are set as appropriate (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal -u k3s | grep -m1 'Running kube-apiserver'

Expected Result: '--etcd-certfile' is present AND '--etcd-keyfile' is present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.27 Ensure that the --tls-cert-file and --tls-private-key-file arguments are set as appropriate (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal -u k3s | grep -A1 'Running kube-apiserver' | tail -n2

Expected Result: '--tls-cert-file' is present AND '--tls-private-key-file' is present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"
May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-scheduler --authentication-kubeconfig=/var/lib/rancher/k3s/server/cred/scheduler.kubeconfig --authorization-kubeconfig=/var/lib/rancher/k3s/server/cred/scheduler.kubeconfig --bind-address=127.0.0.1 --kubeconfig=/var/lib/rancher/k3s/server/cred/scheduler.kubeconfig --profiling=false --secure-port=10259"

1.2.28 Ensure that the --client-ca-file argument is set as appropriate (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'client-ca-file'

Expected Result: '--client-ca-file' is present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.29 Ensure that the --etcd-cafile argument is set as appropriate (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'etcd-cafile'

Expected Result: '--etcd-cafile' is present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.30 Ensure that the --encryption-provider-config argument is set as appropriate (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'encryption-provider-config'

Expected Result: '--encryption-provider-config' is present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.2.31 Ensure that encryption providers are appropriately configured (Automated)

Result: WARN

Remediation: Follow the Kubernetes documentation and configure a EncryptionConfig file. In this file, choose aescbc, kms or secretbox as the encryption provider.

1.2.32 Ensure that the API Server only makes use of Strong Cryptographic Ciphers (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-apiserver' | tail -n1 | grep 'tls-cipher-suites'

Expected Result: '--tls-cipher-suites' contains valid elements from 'TLS_AES_128_GCM_SHA256,TLS_AES_256_GCM_SHA384,TLS_CHACHA20_POLY1305_SHA256,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,TLS_RSA_WITH_3DES_EDE_CBC_SHA,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_256_GCM_SHA384'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

1.3 Controller Manager

1.3.1 Ensure that the --terminated-pod-gc-threshold argument is set as appropriate (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-controller-manager' | tail -n1 | grep 'terminated-pod-gc-threshold'

Expected Result: '--terminated-pod-gc-threshold' is present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-controller-manager --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/k3s/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/k3s/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/k3s/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/k3s/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/k3s/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/k3s/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/k3s/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/k3s/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/k3s/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --terminated-pod-gc-threshold=10 --use-service-account-credentials=true"

1.3.2 Ensure that the --profiling argument is set to false (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-controller-manager' | tail -n1 | grep 'profiling'

Expected Result: '--profiling' is equal to 'false'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-controller-manager --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/k3s/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/k3s/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/k3s/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/k3s/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/k3s/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/k3s/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/k3s/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/k3s/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/k3s/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --terminated-pod-gc-threshold=10 --use-service-account-credentials=true"

1.3.3 Ensure that the --use-service-account-credentials argument is set to true (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-controller-manager' | tail -n1 | grep 'use-service-account-credentials'

Expected Result: '--use-service-account-credentials' is not equal to 'false'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-controller-manager --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/k3s/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/k3s/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/k3s/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/k3s/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/k3s/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/k3s/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/k3s/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/k3s/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/k3s/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --terminated-pod-gc-threshold=10 --use-service-account-credentials=true"

1.3.4 Ensure that the --service-account-private-key-file argument is set as appropriate (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-controller-manager' | tail -n1 | grep 'service-account-private-key-file'

Expected Result: '--service-account-private-key-file' is present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-controller-manager --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/k3s/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/k3s/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/k3s/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/k3s/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/k3s/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/k3s/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/k3s/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/k3s/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/k3s/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --terminated-pod-gc-threshold=10 --use-service-account-credentials=true"

1.3.5 Ensure that the --root-ca-file argument is set as appropriate (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-controller-manager' | tail -n1 | grep 'root-ca-file'

Expected Result: '--root-ca-file' is present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-controller-manager --allocate-node-cidrs=true --authentication-kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --authorization-kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --bind-address=127.0.0.1 --cluster-cidr=10.42.0.0/16 --cluster-signing-kube-apiserver-client-cert-file=/var/lib/rancher/k3s/server/tls/client-ca.nochain.crt --cluster-signing-kube-apiserver-client-key-file=/var/lib/rancher/k3s/server/tls/client-ca.key --cluster-signing-kubelet-client-cert-file=/var/lib/rancher/k3s/server/tls/client-ca.nochain.crt --cluster-signing-kubelet-client-key-file=/var/lib/rancher/k3s/server/tls/client-ca.key --cluster-signing-kubelet-serving-cert-file=/var/lib/rancher/k3s/server/tls/server-ca.nochain.crt --cluster-signing-kubelet-serving-key-file=/var/lib/rancher/k3s/server/tls/server-ca.key --cluster-signing-legacy-unknown-cert-file=/var/lib/rancher/k3s/server/tls/server-ca.nochain.crt --cluster-signing-legacy-unknown-key-file=/var/lib/rancher/k3s/server/tls/server-ca.key --configure-cloud-routes=false --controllers=*,tokencleaner,-service,-route,-cloud-node-lifecycle --feature-gates=JobTrackingWithFinalizers=true --kubeconfig=/var/lib/rancher/k3s/server/cred/controller.kubeconfig --profiling=false --root-ca-file=/var/lib/rancher/k3s/server/tls/server-ca.crt --secure-port=10257 --service-account-private-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --terminated-pod-gc-threshold=10 --use-service-account-credentials=true"

1.3.6 Ensure that the RotateKubeletServerCertificate argument is set to true (Automated)

Result: Not Applicable

Remediation: Edit the Controller Manager pod specification file /etc/kubernetes/manifests/kube-controller-manager.yaml on the control plane node and set the --feature-gates parameter to include RotateKubeletServerCertificate=true. --feature-gates=RotateKubeletServerCertificate=true

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

Result: PASS

Audit:

/bin/ps -ef | grep containerd | grep -v grep

Expected Result: '--bind-address' is present OR '--bind-address' is not present

Returned Value:

root        2335    2318  0 18:38 ?        00:00:00 containerd -c /var/lib/rancher/k3s/agent/etc/containerd/config.toml -a /run/k3s/containerd/containerd.sock --state /run/k3s/containerd --root /var/lib/rancher/k3s/agent/containerd

1.4 Scheduler

1.4.1 Ensure that the --profiling argument is set to false (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal -u k3s | grep 'Running kube-scheduler' | tail -n1

Expected Result: '--profiling' is equal to 'false'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-scheduler --authentication-kubeconfig=/var/lib/rancher/k3s/server/cred/scheduler.kubeconfig --authorization-kubeconfig=/var/lib/rancher/k3s/server/cred/scheduler.kubeconfig --bind-address=127.0.0.1 --kubeconfig=/var/lib/rancher/k3s/server/cred/scheduler.kubeconfig --profiling=false --secure-port=10259"

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

Result: PASS

Audit:

journalctl -D /var/log/journal  -u k3s | grep 'Running kube-scheduler' | tail -n1 | grep 'bind-address'

Expected Result: '--bind-address' is equal to '127.0.0.1' OR '--bind-address' is not present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-scheduler --authentication-kubeconfig=/var/lib/rancher/k3s/server/cred/scheduler.kubeconfig --authorization-kubeconfig=/var/lib/rancher/k3s/server/cred/scheduler.kubeconfig --bind-address=127.0.0.1 --kubeconfig=/var/lib/rancher/k3s/server/cred/scheduler.kubeconfig --profiling=false --secure-port=10259"

2 Etcd Node Configuration

2.1 Ensure that the --cert-file and --key-file arguments are set as appropriate (Automated)

Result: PASS

Audit:

grep -A 4 'client-transport-security' /var/lib/rancher/k3s/server/db/etcd/config | grep -E 'cert-file|key-file'

Expected Result: 'cert-file' is present AND 'key-file' is present

Returned Value:

  cert-file: /var/lib/rancher/k3s/server/tls/etcd/server-client.crt
  key-file: /var/lib/rancher/k3s/server/tls/etcd/server-client.key

2.2 Ensure that the --client-cert-auth argument is set to true (Automated)

Result: PASS

Audit:

grep -A 4 'client-transport-security' /var/lib/rancher/k3s/server/db/etcd/config | grep 'client-cert-auth'

Expected Result: '--client-cert-auth' is present OR 'client-cert-auth' is equal to 'true'

Returned Value:

  client-cert-auth: true

2.3 Ensure that the --auto-tls argument is not set to true (Automated)

Result: PASS

Audit:

if grep -q '^auto-tls' /var/lib/rancher/k3s/server/db/etcd/config;then grep '^auto-tls' /var/lib/rancher/k3s/server/db/etcd/config;else echo 'notset';fi

Expected Result: '--auto-tls' is not present OR '--auto-tls' is present

Returned Value:

notset

2.4 Ensure that the --peer-cert-file and --peer-key-file arguments are set as appropriate (Automated)

Result: PASS

Audit:

grep -A 4 'peer-transport-security' /var/lib/rancher/k3s/server/db/etcd/config | grep -E 'cert-file|key-file'

Expected Result: 'cert-file' is present AND 'key-file' is present

Returned Value:

  cert-file: /var/lib/rancher/k3s/server/tls/etcd/peer-server-client.crt
  key-file: /var/lib/rancher/k3s/server/tls/etcd/peer-server-client.key

2.5 Ensure that the --peer-client-cert-auth argument is set to true (Automated)

Result: PASS

Audit:

grep -A 4 'peer-transport-security' /var/lib/rancher/k3s/server/db/etcd/config | grep 'client-cert-auth'

Expected Result: '--client-cert-auth' is present OR 'client-cert-auth' is equal to 'true'

Returned Value:

  client-cert-auth: true

2.6 Ensure that the --peer-auto-tls argument is not set to true (Automated)

Result: PASS

Audit:

if grep -q '^peer-auto-tls' /var/lib/rancher/k3s/server/db/etcd/config;then grep '^peer-auto-tls' /var/lib/rancher/k3s/server/db/etcd/config;else echo 'notset';fi

Expected Result: '--peer-auto-tls' is not present OR '--peer-auto-tls' is present

Returned Value:

notset

2.7 Ensure that a unique Certificate Authority is used for etcd (Automated)

Result: PASS

Audit:

if grep -q 'trusted-ca-file' /var/lib/rancher/k3s/server/db/etcd/config;then grep 'trusted-ca-file' /var/lib/rancher/k3s/server/db/etcd/config;else echo 'notset';fi

Expected Result: 'trusted-ca-file' is present

Returned Value:

  trusted-ca-file: /var/lib/rancher/k3s/server/tls/etcd/server-ca.crt
  trusted-ca-file: /var/lib/rancher/k3s/server/tls/etcd/peer-ca.crt

4.1 Worker Node Configuration Files

4.1.1 Ensure that the kubelet service file permissions are set to 600 or more restrictive (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the each worker node. For example, chmod 600 /etc/systemd/system/kubelet.service.d/10-kubeadm.conf

4.1.2 Ensure that the kubelet service file ownership is set to root:root (Automated)

Result: Not Applicable

Remediation: Run the below command (based on the file location on your system) on the each worker node. For example, chown root:root /etc/systemd/system/kubelet.service.d/10-kubeadm.conf

4.1.3 If proxy kubeconfig file exists ensure permissions are set to 600 or more restrictive (Manual)

Result: WARN

Remediation: Run the below command (based on the file location on your system) on the each worker node. For example, chmod 600 /var/lib/rancher/k3s/agent/kubeproxy.kubeconfig

4.1.4 If proxy kubeconfig file exists ensure ownership is set to root:root (Manual)

Result: PASS

Audit:

/bin/sh -c 'if test -e /var/lib/rancher/k3s/agent/kubeproxy.kubeconfig; then stat -c %U:%G /var/lib/rancher/k3s/agent/kubeproxy.kubeconfig; fi' 

Expected Result: 'root:root' is present

Returned Value:

root:root

4.1.5 Ensure that the --kubeconfig kubelet.conf file permissions are set to 600 or more restrictive (Automated)

Result: PASS

Audit:

stat -c %a /var/lib/rancher/k3s/agent/kubelet.kubeconfig 

Expected Result: '600' is equal to '600'

Returned Value:

600

4.1.6 Ensure that the --kubeconfig kubelet.conf file ownership is set to root:root (Automated)

Result: PASS

Audit:

stat -c %U:%G /var/lib/rancher/k3s/agent/kubelet.kubeconfig

Expected Result: 'root:root' is equal to 'root:root'

Returned Value:

root:root

4.1.7 Ensure that the certificate authorities file permissions are set to 600 or more restrictive (Manual)

Result: WARN

Remediation: Run the following command to modify the file permissions of the --client-ca-file chmod 600 <filename>

4.1.8 Ensure that the client certificate authorities file ownership is set to root:root (Manual)

Result: PASS

Audit:

stat -c %U:%G /var/lib/rancher/k3s/server/tls/client-ca.crt

Expected Result: 'root:root' is present

Returned Value:

root:root

4.1.9 If the kubelet config.yaml configuration file is being used validate permissions set to 600 or more restrictive (Manual)

Result: Not Applicable

Remediation: Run the following command (using the config file location identified in the Audit step) chmod 600 /var/lib/kubelet/config.yaml

4.1.10 If the kubelet config.yaml configuration file is being used validate file ownership is set to root:root (Manual)

Result: Not Applicable

Remediation: Run the following command (using the config file location identified in the Audit step) chown root:root /var/lib/kubelet/config.yaml

4.2 Kubelet

4.2.1 Ensure that the --anonymous-auth argument is set to false (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test $(journalctl -D /var/log/journal -u k3s | grep "Running kube-apiserver" | wc -l) -gt 0; then journalctl -D /var/log/journal -u k3s | grep "Running kube-apiserver" | tail -n1 | grep "anonymous-auth" | grep -v grep; else echo "--anonymous-auth=false"; fi' 

Expected Result: '--anonymous-auth' is equal to 'false'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

4.2.2 Ensure that the --authorization-mode argument is not set to AlwaysAllow (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test $(journalctl -D /var/log/journal -u k3s | grep "Running kube-apiserver" | wc -l) -gt 0; then journalctl -D /var/log/journal -u k3s | grep "Running kube-apiserver" | tail -n1 | grep "authorization-mode" | grep -v grep; else echo "--authorization-mode=Webhook"; fi' 

Expected Result: '--authorization-mode' does not have 'AlwaysAllow'

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

4.2.3 Ensure that the --client-ca-file argument is set as appropriate (Automated)

Result: PASS

Audit:

/bin/sh -c 'if test $(journalctl -D /var/log/journal -u k3s | grep "Running kube-apiserver" | wc -l) -gt 0; then journalctl -D /var/log/journal -u k3s | grep "Running kube-apiserver" | tail -n1 | grep "client-ca-file" | grep -v grep; else echo "--client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt"; fi' 

Expected Result: '--client-ca-file' is present

Returned Value:

May 15 18:38:23 server-0 k3s[2318]: time="2024-05-15T18:38:23Z" level=info msg="Running kube-apiserver --advertise-address=10.10.10.100 --advertise-port=6443 --allow-privileged=true --anonymous-auth=false --api-audiences=https://kubernetes.default.svc.cluster.local,k3s --audit-log-maxage=30 --audit-log-maxbackup=10 --audit-log-maxsize=100 --audit-log-path=/var/lib/rancher/k3s/server/logs/audit.log --audit-policy-file=/var/lib/rancher/k3s/server/audit.yaml --authorization-mode=Node,RBAC --bind-address=127.0.0.1 --cert-dir=/var/lib/rancher/k3s/server/tls/temporary-certs --client-ca-file=/var/lib/rancher/k3s/server/tls/client-ca.crt --egress-selector-config-file=/var/lib/rancher/k3s/server/etc/egress-selector-config.yaml --enable-admission-plugins=NodeRestriction,NamespaceLifecycle,ServiceAccount,PodSecurityPolicy --enable-aggregator-routing=true --enable-bootstrap-token-auth=true --encryption-provider-config=/var/lib/rancher/k3s/server/cred/encryption-config.json --etcd-cafile=/var/lib/rancher/k3s/server/tls/etcd/server-ca.crt --etcd-certfile=/var/lib/rancher/k3s/server/tls/etcd/client.crt --etcd-keyfile=/var/lib/rancher/k3s/server/tls/etcd/client.key --etcd-servers=https://127.0.0.1:2379 --feature-gates=JobTrackingWithFinalizers=true --kubelet-certificate-authority=/var/lib/rancher/k3s/server/tls/server-ca.crt --kubelet-client-certificate=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.crt --kubelet-client-key=/var/lib/rancher/k3s/server/tls/client-kube-apiserver.key --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname --profiling=false --proxy-client-cert-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.crt --proxy-client-key-file=/var/lib/rancher/k3s/server/tls/client-auth-proxy.key --requestheader-allowed-names=system:auth-proxy --requestheader-client-ca-file=/var/lib/rancher/k3s/server/tls/request-header-ca.crt --requestheader-extra-headers-prefix=X-Remote-Extra- --requestheader-group-headers=X-Remote-Group --requestheader-username-headers=X-Remote-User --secure-port=6444 --service-account-issuer=https://kubernetes.default.svc.cluster.local --service-account-key-file=/var/lib/rancher/k3s/server/tls/service.key --service-account-lookup=true --service-account-signing-key-file=/var/lib/rancher/k3s/server/tls/service.current.key --service-cluster-ip-range=10.43.0.0/16 --service-node-port-range=30000-32767 --storage-backend=etcd3 --tls-cert-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.crt --tls-cipher-suites=TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,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_CHACHA20_POLY1305 --tls-private-key-file=/var/lib/rancher/k3s/server/tls/serving-kube-apiserver.key"

4.2.4 Verify that the --read-only-port argument is set to 0 (Manual)

Result: PASS

Audit:

journalctl -D /var/log/journal -u k3s | grep 'Running kubelet' | tail -n1 | grep 'read-only-port' 

Expected Result: '--read-only-port' is equal to '0' OR '--read-only-port' is not present

Returned Value:

May 15 18:38:24 server-0 k3s[2318]: time="2024-05-15T18:38:24Z" level=info msg="Running kubelet --address=0.0.0.0 --allowed-unsafe-sysctls=net.ipv4.ip_forward,net.ipv6.conf.all.forwarding --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/k3s/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --event-qps=0 --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/k3s/agent/kubelet.kubeconfig --make-iptables-util-chains=true --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=rancher/mirrored-pause:3.6 --pod-manifest-path=/var/lib/rancher/k3s/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --streaming-connection-idle-timeout=5m --tls-cert-file=/var/lib/rancher/k3s/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/k3s/agent/serving-kubelet.key"

4.2.5 Ensure that the --streaming-connection-idle-timeout argument is not set to 0 (Manual)

Result: PASS

Audit:

journalctl -D /var/log/journal -u k3s | grep 'Running kubelet' | tail -n1 | grep 'streaming-connection-idle-timeout'

Expected Result: '--streaming-connection-idle-timeout' is not equal to '0' OR '--streaming-connection-idle-timeout' is not present

Returned Value:

May 15 18:38:24 server-0 k3s[2318]: time="2024-05-15T18:38:24Z" level=info msg="Running kubelet --address=0.0.0.0 --allowed-unsafe-sysctls=net.ipv4.ip_forward,net.ipv6.conf.all.forwarding --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/k3s/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --event-qps=0 --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/k3s/agent/kubelet.kubeconfig --make-iptables-util-chains=true --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=rancher/mirrored-pause:3.6 --pod-manifest-path=/var/lib/rancher/k3s/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --streaming-connection-idle-timeout=5m --tls-cert-file=/var/lib/rancher/k3s/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/k3s/agent/serving-kubelet.key"

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

Result: Not Applicable

Remediation: If using a Kubelet config file, edit the file to set protectKernelDefaults to true. If using command line arguments, edit the kubelet service file /etc/systemd/system/kubelet.service.d/10-kubeadm.conf 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

4.2.7 Ensure that the --make-iptables-util-chains argument is set to true (Automated)

Result: Not Applicable

Remediation: If using a Kubelet config file, edit the file to set makeIPTablesUtilChains to true. If using command line arguments, edit the kubelet service file /etc/systemd/system/kubelet.service.d/10-kubeadm.conf 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

4.2.8 Ensure that the --hostname-override argument is not set (Manual)

Result: Not Applicable

Remediation: Edit the kubelet service file /etc/systemd/system/kubelet.service.d/10-kubeadm.conf 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

4.2.9 Ensure that the eventRecordQPS argument is set to a level which ensures appropriate event capture (Manual)

Result: WARN

Remediation: If using a Kubelet config file, edit the file to set eventRecordQPS to an appropriate level. If using command line arguments, edit the kubelet service file /etc/systemd/system/kubelet.service.d/10-kubeadm.conf on each worker node and set the below parameter in KUBELET_SYSTEM_PODS_ARGS variable. Based on your system, restart the kubelet service. For example, systemctl daemon-reload systemctl restart kubelet.service

4.2.10 Ensure that the --tls-cert-file and --tls-private-key-file arguments are set as appropriate (Manual)

Result: PASS

Audit:

journalctl -D /var/log/journal -u k3s | grep 'Running kubelet' | tail -n1

Expected Result: '--tls-cert-file' is present AND '--tls-private-key-file' is present

Returned Value:

May 15 18:38:24 server-0 k3s[2318]: time="2024-05-15T18:38:24Z" level=info msg="Running kubelet --address=0.0.0.0 --allowed-unsafe-sysctls=net.ipv4.ip_forward,net.ipv6.conf.all.forwarding --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/k3s/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --event-qps=0 --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/k3s/agent/kubelet.kubeconfig --make-iptables-util-chains=true --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=rancher/mirrored-pause:3.6 --pod-manifest-path=/var/lib/rancher/k3s/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --streaming-connection-idle-timeout=5m --tls-cert-file=/var/lib/rancher/k3s/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/k3s/agent/serving-kubelet.key"

4.2.11 Ensure that the --rotate-certificates argument is not set to false (Automated)

Result: PASS

Audit:

journalctl -D /var/log/journal -u k3s | grep 'Running kubelet' | tail -n1

Expected Result: '--rotate-certificates' is present OR '--rotate-certificates' is not present

Returned Value:

May 15 18:38:24 server-0 k3s[2318]: time="2024-05-15T18:38:24Z" level=info msg="Running kubelet --address=0.0.0.0 --allowed-unsafe-sysctls=net.ipv4.ip_forward,net.ipv6.conf.all.forwarding --anonymous-auth=false --authentication-token-webhook=true --authorization-mode=Webhook --cgroup-driver=systemd --client-ca-file=/var/lib/rancher/k3s/agent/client-ca.crt --cloud-provider=external --cluster-dns=10.43.0.10 --cluster-domain=cluster.local --container-runtime-endpoint=unix:///run/k3s/containerd/containerd.sock --containerd=/run/k3s/containerd/containerd.sock --event-qps=0 --eviction-hard=imagefs.available<5%,nodefs.available<5% --eviction-minimum-reclaim=imagefs.available=10%,nodefs.available=10% --fail-swap-on=false --healthz-bind-address=127.0.0.1 --hostname-override=server-0 --kubeconfig=/var/lib/rancher/k3s/agent/kubelet.kubeconfig --make-iptables-util-chains=true --node-ip=10.10.10.100 --node-labels= --pod-infra-container-image=rancher/mirrored-pause:3.6 --pod-manifest-path=/var/lib/rancher/k3s/agent/pod-manifests --protect-kernel-defaults=true --read-only-port=0 --resolv-conf=/run/systemd/resolve/resolv.conf --serialize-image-pulls=false --streaming-connection-idle-timeout=5m --tls-cert-file=/var/lib/rancher/k3s/agent/serving-kubelet.crt --tls-private-key-file=/var/lib/rancher/k3s/agent/serving-kubelet.key"

4.2.12 Verify that the RotateKubeletServerCertificate argument is set to true (Manual)

Result: WARN

Remediation: Edit the kubelet service file /etc/systemd/system/kubelet.service.d/10-kubeadm.conf 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

4.2.13 Ensure that the Kubelet only makes use of Strong Cryptographic Ciphers (Manual)

Result: WARN

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 or to a subset of these values. If using executable arguments, edit the kubelet service file /etc/systemd/system/kubelet.service.d/10-kubeadm.conf on each worker node and set the --tls-cipher-suites parameter as follows, or to a subset of these values. --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 Based on your system, restart the kubelet service. For example: systemctl daemon-reload systemctl restart kubelet.service

5.1 RBAC and Service Accounts

5.1.1 Ensure that the cluster-admin role is only used where required (Manual)

Result: WARN

Remediation: Identify all clusterrolebindings to the cluster-admin role. Check if they are used and if they need this role or if they could use a role with fewer privileges. Where possible, first bind users to a lower privileged role and then remove the clusterrolebinding to the cluster-admin role : kubectl delete clusterrolebinding [name]

5.1.2 Minimize access to secrets (Manual)

Result: WARN

Remediation: Where possible, remove get, list and watch access to Secret objects in the cluster.

5.1.3 Minimize wildcard use in Roles and ClusterRoles (Manual)

Result: WARN

Remediation: Where possible replace any use of wildcards in clusterroles and roles with specific objects or actions.

5.1.4 Minimize access to create pods (Manual)

Result: WARN

Remediation: Where possible, remove create access to pod objects in the cluster.

5.1.5 Ensure that default service accounts are not actively used. (Manual)

Result: WARN

Remediation: Create explicit service accounts wherever a Kubernetes workload requires specific access to the Kubernetes API server. Modify the configuration of each default service account to include this value automountServiceAccountToken: false

5.1.6 Ensure that Service Account Tokens are only mounted where necessary (Manual)

Result: WARN

Remediation: Modify the definition of pods and service accounts which do not need to mount service account tokens to disable it.

5.1.7 Avoid use of system:masters group (Manual)

Result: WARN

Remediation: Remove the system:masters group from all users in the cluster.

5.1.8 Limit use of the Bind, Impersonate and Escalate permissions in the Kubernetes cluster (Manual)

Result: WARN

Remediation: Where possible, remove the impersonate, bind and escalate rights from subjects.

5.2 Pod Security Standards

5.2.1 Ensure that the cluster has at least one active policy control mechanism in place (Manual)

Result: WARN

Remediation: Ensure that either Pod Security Admission or an external policy control system is in place for every namespace which contains user workloads.

5.2.2 Minimize the admission of privileged containers (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of privileged containers.

5.2.3 Minimize the admission of containers wishing to share the host process ID namespace (Automated)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of hostPID containers.

5.2.4 Minimize the admission of containers wishing to share the host IPC namespace (Automated)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of hostIPC containers.

5.2.5 Minimize the admission of containers wishing to share the host network namespace (Automated)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of hostNetwork containers.

5.2.6 Minimize the admission of containers with allowPrivilegeEscalation (Automated)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of containers with .spec.allowPrivilegeEscalation set to true.

5.2.7 Minimize the admission of root containers (Automated)

Result: WARN

Remediation: Create a policy for each namespace in the cluster, ensuring that either MustRunAsNonRoot or MustRunAs with the range of UIDs not including 0, is set.

5.2.8 Minimize the admission of containers with the NET_RAW capability (Automated)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of containers with the NET_RAW capability.

5.2.9 Minimize the admission of containers with added capabilities (Automated)

Result: WARN

Remediation: Ensure that allowedCapabilities is not present in policies for the cluster unless it is set to an empty array.

5.2.10 Minimize the admission of containers with capabilities assigned (Manual)

Result: WARN

Remediation: Review the use of capabilities in applications running on your cluster. Where a namespace contains applications which do not require any Linux capabities to operate consider adding a PSP which forbids the admission of containers which do not drop all capabilities.

5.2.11 Minimize the admission of Windows HostProcess containers (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of containers that have .securityContext.windowsOptions.hostProcess set to true.

5.2.12 Minimize the admission of HostPath volumes (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of containers with hostPath volumes.

5.2.13 Minimize the admission of containers which use HostPorts (Manual)

Result: WARN

Remediation: Add policies to each namespace in the cluster which has user workloads to restrict the admission of containers which use hostPort sections.

5.3 Network Policies and CNI

5.3.1 Ensure that the CNI in use supports NetworkPolicies (Manual)

Result: WARN

Remediation: If the CNI plugin in use does not support network policies, consideration should be given to making use of a different plugin, or finding an alternate mechanism for restricting traffic in the Kubernetes cluster.

5.3.2 Ensure that all Namespaces have NetworkPolicies defined (Manual)

Result: WARN

Remediation: Follow the documentation and create NetworkPolicy objects as you need them.

5.4 Secrets Management

5.4.1 Prefer using Secrets as files over Secrets as environment variables (Manual)

Result: WARN

Remediation: If possible, rewrite application code to read Secrets from mounted secret files, rather than from environment variables.

5.4.2 Consider external secret storage (Manual)

Result: WARN

Remediation: Refer to the Secrets management options offered by your cloud provider or a third-party secrets management solution.

5.5 Extensible Admission Control

5.5.1 Configure Image Provenance using ImagePolicyWebhook admission controller (Manual)

Result: WARN

Remediation: Follow the Kubernetes documentation and setup image provenance.

5.7 General Policies

5.7.1 Create administrative boundaries between resources using namespaces (Manual)

Result: WARN

Remediation: Follow the documentation and create namespaces for objects in your deployment as you need them.

5.7.2 Ensure that the seccomp profile is set to docker/default in your Pod definitions (Manual)

Result: WARN

Remediation: Use securityContext to enable the docker/default seccomp profile in your pod definitions. An example is as below: securityContext: seccompProfile: type: RuntimeDefault

5.7.3 Apply SecurityContext to your Pods and Containers (Manual)

Result: WARN

Remediation: Follow the Kubernetes documentation and apply SecurityContexts to your Pods. For a suggested list of SecurityContexts, you may refer to the CIS Security Benchmark for Docker Containers.

5.7.4 The default namespace should not be used (Manual)

Result: WARN

Remediation: Ensure that namespaces are created to allow for appropriate segregation of Kubernetes resources and that all new resources are created in a specific namespace.