- Testing controls methodology
- Controls
- 1 - Master Node Security Configuration
- 1.1 - API Server
- 1.1.1 - Ensure that the
--anonymous-auth
argument is set tofalse
(Scored) - 1.1.2 - Ensure that the
--basic-auth-file
argument is not set (Scored) - 1.1.3 - Ensure that the
--insecure-allow-any-token
argument is not set (Scored) - 1.1.4 - Ensure that the
--kubelet-https
argument is set totrue
(Scored) - 1.1.5 - Ensure that the
--insecure-bind-address
argument is not set (Scored) - 1.1.6 - Ensure that the
--insecure-port argument
is set to0
(Scored) - 1.1.7 - Ensure that the
--secure-port
argument is not set to0
(Scored) - 1.1.8 - Ensure that the
--profiling
argument is set tofalse
(Scored) - 1.1.9 - Ensure that the
--repair-malformed-updates
argument is set tofalse
(Scored) - 1.1.10 - Ensure that the admission control plugin
AlwaysAdmit
is not set (Scored) - 1.1.11 - Ensure that the admission control plugin
AlwaysPullImages
is set (Scored) - 1.1.12 - Ensure that the admission control plugin
DenyEscalatingExec
is set (Scored) - 1.1.13 - Ensure that the admission control plugin
SecurityContextDeny
is set (Not Scored) - 1.1.14 - Ensure that the admission control plugin
NamespaceLifecycle
is set (Scored) - 1.1.15 - Ensure that the
--audit-log-path
argument is set as appropriate (Scored) - 1.1.16 - Ensure that the
--audit-log-maxage
argument is set to30
or as appropriate (Scored) - 1.1.17 - Ensure that the
--audit-log-maxbackup
argument is set to10
or as appropriate (Scored) - 1.1.18 - Ensure that the
--audit-log-maxsize
argument is set to100
or as appropriate (Scored) - 1.1.19 - Ensure that the
--authorization-mode
argument is not set toAlwaysAllow
(Scored) - 1.1.20 - Ensure that the
--token-auth-file
parameter is not set (Scored) - 1.1.21 - Ensure that the
--kubelet-certificate-authority
argument is set as appropriate (Scored) - 1.1.22 - Ensure that the
--kubelet-client-certificate
and--kubelet-client-key
arguments are set as appropriate (Scored) - 1.1.23 Ensure that the
--service-account-lookup
argument is set totrue
(Scored) - 1.1.24 - Ensure that the admission control plugin
PodSecurityPolicy
is set (Scored) - 1.1.25 - Ensure that the
--service-account-key-file
argument is set as appropriate (Scored) - 1.1.26 - Ensure that the
--etcd-certfile
and--etcd-keyfile
arguments are set as appropriate (Scored) - 1.1.27 - Ensure that the admission control plugin
ServiceAccount
is set (Scored) - 1.1.28 - Ensure that the
--tls-cert-file
and--tls-private-key-file
arguments are set as appropriate (Scored) - 1.1.29 - Ensure that the
--client-ca-file
argument is set as appropriate (Scored) - 1.1.30 - Ensure that the API Server only makes use of strong cryptographic ciphers (Not Scored)
- 1.1.31 - Ensure that the
--etcd-cafile
argument is set as appropriate (Scored) - 1.1.32 - Ensure that the
--authorization-mode
argument includes Node (Scored) - 1.1.33 - Ensure that the admission control plugin
NodeRestriction
is set (Scored) - 1.1.34 - Ensure that the
--experimental-encryption-provider-config
argument is set as appropriate (Scored) - 1.1.35 - Ensure that the encryption provider is set to aescbc (Scored)
- 1.1.36 - Ensure that the admission control plugin
EventRateLimit
is set (Scored) - 1.1.37 Ensure that the AdvancedAuditing argument is not set to false (Scored)
- 1.1.38 Ensure that the
--request-timeout
argument is set as appropriate (Scored) - Ensure that the –authorization-mode argument includes RBAC (Scored)
- 1.1.1 - Ensure that the
- 1.2 - Scheduler
- 1.3 - Controller Manager
- 1.3.1 - Ensure that the
--terminated-pod-gc-threshold
argument is set as appropriate (Scored) - 1.3.2 - Ensure that the
--profiling
argument is set to false (Scored) - 1.3.3 - Ensure that the
--use-service-account-credentials
argument is set to true (Scored) - 1.3.4 - Ensure that the
--service-account-private-key-file
argument is set as appropriate (Scored) - 1.3.5 - Ensure that the
--root-ca-file
argument is set as appropriate (Scored) - 1.3.6 - Ensure that the RotateKubeletServerCertificate argument is set to true (Scored)
- 1.3.7 - Ensure that the
--address
argument is set to 127.0.0.1 (Scored)
- 1.3.1 - Ensure that the
- 1.4 - Configuration Files
- 1.4.1 - Ensure that the API server pod specification file permissions are set to 644 or more restrictive (Scored)
- 1.4.2 - Ensure that the API server pod specification file ownership is set to
root:root
(Scored) - 1.4.3 - Ensure that the controller manager pod specification file permissions are set to
644
or more restrictive (Scored) - 1.4.4 - Ensure that the controller manager pod specification file ownership is set to
root:root
(Scored) - 1.4.5 - Ensure that the scheduler pod specification file permissions are set to
644
or more restrictive (Scored) - 1.4.6 - Ensure that the scheduler pod specification file ownership is set to
root:root
(Scored) - 1.4.7 - Ensure that the
etcd
pod specification file permissions are set to644
or more restrictive (Scored) - 1.4.8 - Ensure that the
etcd
pod specification file ownership is set toroot:root
(Scored) - 1.4.9 - Ensure that the Container Network Interface file permissions are set to
644
or more restrictive (Not Scored) - 1.4.10 - Ensure that the Container Network Interface file ownership is set to
root:root
(Not Scored) - 1.4.11 - Ensure that the etcd data directory permissions are set to
700
or more restrictive (Scored) - 1.4.12 - Ensure that the
etcd
data directory ownership is set toetcd:etcd
(Scored) - 1.4.13 - Ensure that the file permissions for
admin.conf
are set to644
or more restrictive (Scored) - 1.4.14 - Ensure that ownership of
admin.conf
is set toroot:root
(Scored) - 1.4.15 - Ensure that the file permissions for
scheduler.conf
are set to644
or more restrictive (Scored) - 1.4.16 - Ensure that the file ownership of
scheduler.conf
is set toroot:root
(Scored) - 1.4.17 - Ensure that the file permissions for
controller-manager.conf
are set to644
or more restrictive (Scored) - 1.4.18 - Ensure that the file ownership of
controller-manager.conf
is set toroot:root
(Scored) - 1.4.19 - Ensure that the Kubernetes PKI directory and file ownership is set to root:root (Scored)
- 1.4.20 - Ensure that the Kubernetes PKI certificate file permissions are set to
644
or more restrictive (Scored) - 1.4.21 - Ensure that the Kubernetes PKI key file permissions are set to 600 (Scored)
- 1.5 - etcd
- 1.5.1 - Ensure that the
--cert-file
and--key-file
arguments are set as appropriate (Scored) - 1.5.2 - Ensure that the
--client-cert-auth
argument is set totrue
(Scored) - 1.5.3 - Ensure that the
--auto-tls
argument is not set totrue
(Scored) - 1.5.4 - Ensure that the
--peer-cert-file
and--peer-key-file
arguments are set as appropriate (Scored) - 1.5.5 - Ensure that the
--peer-client-cert-auth
argument is set totrue
(Scored) - 1.5.6 - Ensure that the
--peer-auto-tls
argument is not set totrue
(Scored) - 1.5.7 - Ensure that a unique Certificate Authority is used for
etcd
(Not Scored) - 1.6 - General Security Primitives
- 1.6.1 - Ensure that the cluster-admin role is only used where required (Not Scored)
- 1.6.2 - Create administrative boundaries between resources using namespaces (Not Scored)
- 1.6.3 - Create network segmentation using Network Policies (Not Scored)
- 1.6.4 - Ensure that the
seccomp
profile is set todocker/default
in your pod definitions (Not Scored) - 1.6.5 - Apply security context to your pods and containers (Not Scored)
- 1.6.6 - Configure image provenance using the
ImagePolicyWebhook
admission controller (Not Scored) - 1.6.7 - Configure network policies as appropriate (Not Scored)
- 1.6.8 - Place compensating controls in the form of PodSecurityPolicy (PSP) and RBAC for privileged container usage (Not Scored)
- 1.7 - Pod Security Policies (PSP)
- 1.7.1 - Do not admit privileged containers (Not Scored)
- 1.7.2 - Do not admit containers wishing to share the host process ID namespace (Scored)
- 1.7.3 - Do not admit containers wishing to share the host IPC namespace (Scored)
- 1.7.4 - Do not admit containers wishing to share the host network namespace (Scored)
- 1.7.5 - Do not admit containers with
allowPrivilegeEscalation
(Scored) - 1.7.6 - Do not admit containers whose processes run as
root
(Not Scored) - 1.7.7 - Do not admit containers with dangerous capabilities (Not Scored)
- 1.5.1 - Ensure that the
- 1.1 - API Server
- 2 - Worker Node Security Configuration
- 2.1 - Kubelet
- 2.1.1 - Ensure that the
--anonymous-auth
argument is set tofalse
(Scored) - 2.1.2 - Ensure that the
--authorization-mode
argument is not set toAlwaysAllow
(Scored) - 2.1.3 - Ensure that the
--client-ca-file
argument is set as appropriate (Scored) - 2.1.4 - Ensure that the
--read-only-port
argument is set to0
(Scored) - 2.1.5 - Ensure that the
--streaming-connection-idle-timeout
argument is not set to0
(Scored) - 2.1.6 - Ensure that the
--protect-kernel-defaults
argument is set totrue
(Scored) - 2.1.7 - Ensure that the
--make-iptables-util-chains
argument is set totrue
(Scored) - 2.1.8 - Ensure that the
--hostname-override
argument is not set (Scored) - 2.1.9 - Ensure that the
--event-qps
argument is set to0
(Scored) - 2.1.10 - Ensure that the
--tls-cert-file
and--tls-private-key-file
arguments are set as appropriate (Scored) - 2.1.11 - Ensure that the
--cadvisor-port
argument is set to0
(Scored) - 2.1.12 - Ensure that the
--rotate-certificates
argument is not set tofalse
(Scored) - 2.1.13 - Ensure that the
RotateKubeletServerCertificate
argument is set totrue
(Scored) - 2.1.14 - Ensure that the kubelet only makes use of strong cryptographic ciphers (Not Scored)
- 2.1.1 - Ensure that the
- 2.2 - Configuration Files
- 2.2.1 - Ensure that the permissions for
kubelet.conf
are set to644
or more restrictive (Scored) - 2.2.2 - Ensure that the kubelet.conf file ownership is set to root:root (Scored)
- 2.2.3 - Ensure that the kubelet service file permissions are set to
644
or more restrictive (Scored) - 2.2.4 - Ensure that the kubelet service file ownership is set to
root:root
(Scored) - 2.2.5 - Ensure that the proxy kubeconfig file permissions are set to
644
or more restrictive (Scored) - 2.2.6 - Ensure that the proxy kubeconfig file ownership is set to
root:root
(Scored) - 2.2.7 - Ensure that the certificate authorities file permissions are set to
644
or more restrictive (Scored) - 2.2.8 - Ensure that the client certificate authorities file ownership is set to
root:root
(Scored) - 2.2.9 - Ensure that the kubelet configuration file ownership is set to
root:root
(Scored) - 2.2.10 - Ensure that the kubelet configuration file permissions are set to
644
or more restrictive (Scored)
- 2.2.1 - Ensure that the permissions for
- 2.1 - Kubelet
This document is a companion to the Rancher v2.3 security hardening guide. The hardening guide provides prescriptive guidance for hardening a production installation of Rancher, and this benchmark guide is meant to help you evaluate the level of security of the hardened cluster against each control in the benchmark.
This guide corresponds to specific versions of the hardening guide, Rancher, Kubernetes, and the CIS Benchmark:
Self Assessment Guide Version | Rancher Version | Hardening Guide Version | Kubernetes Version | CIS Benchmark Version |
---|---|---|---|---|
Self Assessment Guide v2.3 | Rancher v2.3.0-2.3.2 | Hardening Guide v2.3 | Kubernetes 1.15 | Benchmark v1.4.1 |
Click here to download a PDF version of this document
The CIS Benchmark version v1.4.1 covers the security posture of Kubernetes 1.13 clusters. This self-assessment has been run against Kubernetes 1.15, using the guidelines outlined in the CIS v1.4.1 benchmark. Updates to the CIS benchmarks will be applied to this document as they are released.
Because Rancher and RKE install Kubernetes services as Docker containers, many of the control verification checks in the CIS Kubernetes Benchmark don’t apply. This guide will walk through the various controls and provide updated example commands to audit compliance in Rancher-created clusters.
This document is to be used by Rancher operators, security teams, auditors and decision makers.
For more detail about each audit, including rationales and remediations for failing tests, you can refer to the corresponding section of the CIS Kubernetes Benchmark v1.4.1. You can download the benchmark after logging in to CISecurity.org.
Testing controls methodology
Rancher and RKE install Kubernetes services via Docker containers. Configuration is defined by arguments passed to the container at the time of initialization, not via configuration files.
Scoring the commands is different in Rancher Labs than in the CIS Benchmark. Where the commands differ from the original CIS benchmark, the commands specific to Rancher Labs are provided for testing.
When performing the tests, you will need access to the Docker command line on the hosts of all three RKE roles. The commands also make use of the the jq
command to provide human-readable formatting.
Controls
1 - Master Node Security Configuration
1.1 - API Server
1.1.1 - Ensure that the --anonymous-auth
argument is set to false
(Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--anonymous-auth=false").string'
Returned Value: --anonymous-auth=false
Result: Pass
1.1.2 - Ensure that the --basic-auth-file
argument is not set (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--basic-auth-file=.*").string'
Returned Value: null
Result: Pass
1.1.3 - Ensure that the --insecure-allow-any-token
argument is not set (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--insecure-allow-any-token").string'
Returned Value: null
Result: Pass
1.1.4 - Ensure that the --kubelet-https
argument is set to true
(Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--kubelet-https=false").string'
Returned Value: null
Result: Pass
1.1.5 - Ensure that the --insecure-bind-address
argument is not set (Scored)
Notes
Flag not set or --insecure-bind-address=127.0.0.1
. RKE sets this flag to --insecure-bind-address=127.0.0.1
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--insecure-bind-address=(?:(?!127\\.0\\.0\\.1).)+")'
Returned Value: null
Result: Pass
1.1.6 - Ensure that the --insecure-port argument
is set to 0
(Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--insecure-port=0").string'
Returned Value: --insecure-port=0
Result: Pass
1.1.7 - Ensure that the --secure-port
argument is not set to 0
(Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--secure-port=6443").string'
Returned Value: --secure-port=6443
Result: Pass
1.1.8 - Ensure that the --profiling
argument is set to false
(Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--profiling=false").string'
Returned Value: --profiling=false
Result: Pass
1.1.9 - Ensure that the --repair-malformed-updates
argument is set to false
(Scored)
Note: This deprecated flag was removed in 1.14, so it cannot be set.
Result: Not Applicable
1.1.10 - Ensure that the admission control plugin AlwaysAdmit
is not set (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--enable-admission-plugins=.*(AlwaysAdmit).*").captures[].string'
Returned Value: null
Result: Pass
1.1.11 - Ensure that the admission control plugin AlwaysPullImages
is set (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--enable-admission-plugins=.*(AlwaysPullImages).*").captures[].string'
Returned Value: AlwaysPullImages
Result: Pass
1.1.12 - Ensure that the admission control plugin DenyEscalatingExec
is set (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--enable-admission-plugins=.*(DenyEscalatingExec).*").captures[].string'
Returned Value: DenyEscalatingExec
Result: Pass
1.1.13 - Ensure that the admission control plugin SecurityContextDeny
is set (Not Scored)
Notes
This SHOULD NOT be set if you are using a PodSecurityPolicy
(PSP). From the CIS Benchmark document:
This admission controller should only be used where Pod Security Policies cannot be used on the cluster, as it can interact poorly with certain Pod Security Policies
Several system services (such as nginx-ingress
) utilize SecurityContext
to switch users and assign capabilities. These exceptions to the general principle of not allowing privilege or capabilities can be managed with PSP.
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--enable-admission-plugins=.*(SecurityContextDeny).*").captures[].string'
Returned Value: null
Result: Document
1.1.14 - Ensure that the admission control plugin NamespaceLifecycle
is set (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--enable-admission-plugins=.*(NamespaceLifecycle).*").captures[].string'
Returned Value: NamespaceLifecycle
Result: Pass
1.1.15 - Ensure that the --audit-log-path
argument is set as appropriate (Scored)
Notes
This path is the path inside of the container. It’s combined with the RKE cluster.yml
extra-binds:
option to map the audit log to the host filesystem.
Audit logs should be collected and shipped off-system to guarantee their integrity.
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--audit-log-path=/var/log/kube-audit/audit-log.json").string'
Returned Value: --audit-log-log=/var/log/kube-audit/audit-log.json
Result: Pass
1.1.16 - Ensure that the --audit-log-maxage
argument is set to 30
or as appropriate (Scored)
Notes
Audit logs should be collected and shipped off-system to guarantee their integrity. Rancher Labs recommends setting this argument to a low value to prevent audit logs from filling the local disk.
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--audit-log-maxage=\\d+").string'
Returned Value: --audit-log-maxage=5
Result: Pass
1.1.17 - Ensure that the --audit-log-maxbackup
argument is set to 10
or as appropriate (Scored)
Notes
Audit logs should be collected and shipped off-system to guarantee their integrity. Rancher Labs recommends setting this argument to a low value to prevent audit logs from filling the local disk.
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--audit-log-maxbackup=\\d+").string'
Returned Value: --audit-log-maxbackup=5
Result: Pass
1.1.18 - Ensure that the --audit-log-maxsize
argument is set to 100
or as appropriate (Scored)
Notes
Audit logs should be collected and shipped off-system to guarantee their integrity.
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--audit-log-maxsize=\\d+").string'
Returned Value: --audit-log-maxsize=100
Result: Pass
1.1.19 - Ensure that the --authorization-mode
argument is not set to AlwaysAllow
(Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--authorization-mode=(Node|RBAC|,)+").string'
Returned Value: --authorization-mode=Node,RBAC
Result: Pass
1.1.20 - Ensure that the --token-auth-file
parameter is not set (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--token-auth-file=.*").string'
Returned Value: null
Result: Pass
1.1.21 - Ensure that the --kubelet-certificate-authority
argument is set as appropriate (Scored)
Notes
RKE is using the kubelet’s ability to automatically create self-signed certs. No CA cert is saved to verify the communication between kube-apiserver
and kubelet
.
Mitigation
Make sure nodes with role:controlplane
are on the same local network as your nodes with role:worker
. Use network ACLs to restrict connections to the kubelet port (10250/tcp) on worker nodes, only permitting it from controlplane nodes.
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--kubelet-certificate-authority=.*").string'
Returned Value: none
Result: Pass
1.1.22 - Ensure that the --kubelet-client-certificate
and --kubelet-client-key
arguments are set as appropriate (Scored)
Audit (--kubelet-client-certificate
)
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--kubelet-client-certificate=.*").string'
Returned Value: --kubelet-client-certificate=/etc/kubernetes/ssl/kube-apiserver.pem
Audit (--kubelet-client-key
)
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--kubelet-client-key=.*").string'
Returned Value: --kubelet-client-key=/etc/kubernetes/ssl/kube-apiserver-key.pem
Result: Pass
1.1.23 Ensure that the --service-account-lookup
argument is set to true
(Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--service-account-lookup=true").string'
Returned Value: --service-account-lookup=true
Result: Pass
1.1.24 - Ensure that the admission control plugin PodSecurityPolicy
is set (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--enable-admission-plugins=.*(PodSecurityPolicy).*").captures[].string'
Returned Value: PodSecurityPolicy
Result: Pass
1.1.25 - Ensure that the --service-account-key-file
argument is set as appropriate (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--service-account-key-file=.*").string'
Returned Value: --service-account-key-file=/etc/kubernetes/ssl/kube-service-account-token-key.pem
Result: Pass
1.1.26 - Ensure that the --etcd-certfile
and --etcd-keyfile
arguments are set as appropriate (Scored)
Audit (--etcd-certfile
)
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--etcd-certfile=.*").string'
Returned Value: --etcd-certfile=/etc/kubernetes/ssl/kube-node.pem
Audit (--etcd-keyfile
)
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--etcd-keyfile=.*").string'
Returned Value: --etcd-keyfile=/etc/kubernetes/ssl/kube-node-key.pem
Result: Pass
1.1.27 - Ensure that the admission control plugin ServiceAccount
is set (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--enable-admission-plugins=.*(ServiceAccount).*").captures[].string'
Returned Value: ServiceAccount
Result: Pass
1.1.28 - Ensure that the --tls-cert-file
and --tls-private-key-file
arguments are set as appropriate (Scored)
Audit (--tls-cert-file
)
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--tls-cert-file=.*").string'
Returned Value: --tls-cert-file=/etc/kubernetes/ssl/kube-apiserver.pem
Audit (--tls-key-file
)
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--tls-private-key-file=.*").string'
Returned Value: --tls-private-key-file=/etc/kubernetes/ssl/kube-apiserver-key.pem
Result: Pass
1.1.29 - Ensure that the --client-ca-file
argument is set as appropriate (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--client-ca-file=.*").string'
Returned Value: --client-ca-file=/etc/kubernetes/ssl/kube-ca.pem
Result: Pass
1.1.30 - Ensure that the API Server only makes use of strong cryptographic ciphers (Not Scored)
Audit (Allowed Ciphers)
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256).*").captures[].string'
Returned Value: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256).*").captures[].string'
Returned Value: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305).*").captures[].string'
Returned Value: TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384).*").captures[].string'
Returned Value: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305).*").captures[].string'
Returned Value: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384).*").captures[].string'
Returned Value: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_RSA_WITH_AES_256_GCM_SHA384).*").captures[].string'
Returned Value: TLS_RSA_WITH_AES_256_GCM_SHA384
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_RSA_WITH_AES_128_GCM_SHA256).*").captures[].string'
Returned Value: TLS_RSA_WITH_AES_128_GCM_SHA256
Audit (Disallowed Ciphers)
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(CBC).*").captures[].string'
Returned Value: null
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(RC4).*").captures[].string'
Returned Value: null
Result: Pass
1.1.31 - Ensure that the --etcd-cafile
argument is set as appropriate (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--etcd-cafile=.*").string'
Returned Value: --etcd-cafile=/etc/kubernetes/ssl/kube-ca.pem
Result: Pass
1.1.32 - Ensure that the --authorization-mode
argument includes Node (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--authorization-mode=(Node|RBAC|,)+").string'
Returned Value: --authorization-mode=Node,RBAC
Result: Pass
1.1.33 - Ensure that the admission control plugin NodeRestriction
is set (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--enable-admission-plugins=.*(NodeRestriction).*").captures[].string'
Returned Value: NodeRestriction
Result: Pass
1.1.34 - Ensure that the --experimental-encryption-provider-config
argument is set as appropriate (Scored)
Notes In Kubernetes 1.15.x this flag is --encryption-provider-config
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--encryption-provider-config=.*").string'
Returned Value: encryption-provider-config=/opt/kubernetes/encryption.yaml
Result: Pass
1.1.35 - Ensure that the encryption provider is set to aescbc (Scored)
Notes
Only the first provider in the list is active.
Audit
grep -A 1 providers: /opt/kubernetes/encryption.yaml | grep aescbc
Returned Value: - aescbc:
Result: Pass
1.1.36 - Ensure that the admission control plugin EventRateLimit
is set (Scored)
Notes
The EventRateLimit
plugin requires setting the --admission-control-config-file
option and configuring details in the following files:
/opt/kubernetes/admission.yaml
/opt/kubernetes/event.yaml
See Host Configuration for details.
Audit (Admissions plugin)
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--enable-admission-plugins=.*(EventRateLimit).*").captures[].string'
Returned Value: EventRateLimit
Audit (--admission-control-config-file
)
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--admission-control-config-file=.*").string'
Returned Value: --admission-control-config-file=/opt/kubernetes/admission.yaml
Result: Pass
1.1.37 Ensure that the AdvancedAuditing argument is not set to false (Scored)
Notes
AdvancedAuditing=false
should not be set, but --audit-policy-file
should be set and configured. See Host Configuration for a sample audit policy file.
Audit (Feature Gate)
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--feature-gates=.*(AdvancedAuditing=false).*").captures[].string'
Returned Value: null
Audit (Audit Policy File)
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--audit-policy-file=.*").string'
Returned Value: --audit-policy-file=/opt/kubernetes/audit.yaml
Result: Pass
1.1.38 Ensure that the --request-timeout
argument is set as appropriate (Scored)
Notes
RKE uses the default value of 60s and doesn’t set this option. Tuning this value is specific to the environment.
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--request-timeout=.*").string'
Returned Value: null
Result: Pass
Ensure that the –authorization-mode argument includes RBAC (Scored)
Audit
docker inspect kube-apiserver | jq -e '.[0].Args[] | match("--authorization-mode=.*").string'
Returned Value: "--authorization-mode=Node,RBAC"
Result: Pass
1.2 - Scheduler
1.2.1 - Ensure that the --profiling
argument is set to false (Scored)
Audit
docker inspect kube-scheduler | jq -e '.[0].Args[] | match("--profiling=false").string'
Returned Value: --profiling=false
Result: Pass
1.2.2 - Ensure that the --address
argument is set to 127.0.0.1 (Scored)
Audit
docker inspect kube-scheduler | jq -e '.[0].Args[] | match("--address=127\\.0\\.0\\.1").string'
Returned Value: --address=127.0.0.1
Result: Pass
1.3 - Controller Manager
1.3.1 - Ensure that the --terminated-pod-gc-threshold
argument is set as appropriate (Scored)
Audit
docker inspect kube-controller-manager | jq -e '.[0].Args[] | match("--terminated-pod-gc-threshold=\\d+").string'
Returned Value: --terminated-pod-gc-threshold=1000
Result: Pass
1.3.2 - Ensure that the --profiling
argument is set to false (Scored)
Audit
docker inspect kube-controller-manager | jq -e '.[0].Args[] | match("--profiling=false").string'
Returned Value: --profiling=false
Result: Pass
1.3.3 - Ensure that the --use-service-account-credentials
argument is set to true (Scored)
Audit
docker inspect kube-controller-manager | jq -e '.[0].Args[] | match("--use-service-account-credentials=true").string'
Returned Value: --use-service-account-credentials=true
Result: Pass
1.3.4 - Ensure that the --service-account-private-key-file
argument is set as appropriate (Scored)
Audit
docker inspect kube-controller-manager | jq -e '.[0].Args[] | match("--service-account-private-key-file=.*").string'
Returned Value: --service-account-private-key-file=/etc/kubernetes/ssl/kube-service-account-token-key.pem
Result: Pass
1.3.5 - Ensure that the --root-ca-file
argument is set as appropriate (Scored)
Audit
docker inspect kube-controller-manager | jq -e '.[0].Args[] | match("--root-ca-file=.*").string'
Returned Value: --root-ca-file=/etc/kubernetes/ssl/kube-ca.pem
Result: Pass
1.3.6 - Ensure that the RotateKubeletServerCertificate argument is set to true (Scored)
Notes
RKE handles certificate rotation through an external process.
Result: Not Applicable
1.3.7 - Ensure that the --address
argument is set to 127.0.0.1 (Scored)
Audit
docker inspect kube-controller-manager | jq -e '.[0].Args[] | match("--address=127\\.0\\.0\\.1").string'
Returned Value: --address=127.0.0.1
Result: Pass
1.4 - Configuration Files
1.4.1 - Ensure that the API server pod specification file permissions are set to 644 or more restrictive (Scored)
Notes
RKE doesn’t require or maintain a configuration file for kube-apiserver. All configuration is passed in as arguments at container run time.
Result: Not Applicable
1.4.2 - Ensure that the API server pod specification file ownership is set to root:root
(Scored)
Notes
RKE doesn’t require or maintain a configuration file for kube-apiserver. All configuration is passed in as arguments at container run time.
Result: Not Applicable
1.4.3 - Ensure that the controller manager pod specification file permissions are set to 644
or more restrictive (Scored)
Notes
RKE doesn’t require or maintain a configuration file for kube-controller-manager
. All configuration is passed in as arguments at container run time.
Result: Not Applicable
1.4.4 - Ensure that the controller manager pod specification file ownership is set to root:root
(Scored)
Notes
RKE doesn’t require or maintain a configuration file for kube-controller-manager
. All configuration is passed in as arguments at container run time.
Result: Not Applicable
1.4.5 - Ensure that the scheduler pod specification file permissions are set to 644
or more restrictive (Scored)
Notes
RKE doesn’t require or maintain a configuration file for kube-scheduler
. All configuration is passed in as arguments at container run time.
Result: Not Applicable
1.4.6 - Ensure that the scheduler pod specification file ownership is set to root:root
(Scored)
Notes
RKE doesn’t require or maintain a configuration file for kube-scheduler. All configuration is passed in as arguments at container run time.
Result: Not Applicable
1.4.7 - Ensure that the etcd
pod specification file permissions are set to 644
or more restrictive (Scored)
Notes
RKE doesn’t require or maintain a configuration file for etcd. All configuration is passed in as arguments at container run time.
Result: Not Applicable
1.4.8 - Ensure that the etcd
pod specification file ownership is set to root:root
(Scored)
Notes
RKE doesn’t require or maintain a configuration file for etcd. All configuration is passed in as arguments at container run time.
Result: Not Applicable
1.4.9 - Ensure that the Container Network Interface file permissions are set to 644
or more restrictive (Not Scored)
Notes
This is a manual check.
Audit (/var/lib/cni/networks/k8s-pod-network
)
Note This may return a lockfile. Permissions on this file do not need to be as restrictive as the CNI files.
stat -c "%n - %a" /var/lib/cni/networks/k8s-pod-network/*
Returned Value:
/var/lib/cni/networks/k8s-pod-network/10.42.0.2 - 644
/var/lib/cni/networks/k8s-pod-network/10.42.0.3 - 644
/var/lib/cni/networks/k8s-pod-network/last_reserved_ip.0 - 644
/var/lib/cni/networks/k8s-pod-network/lock - 750
Audit (/etc/cni/net.d
)
stat -c "%n - %a" /etc/cni/net.d/*
Returned Value:
/etc/cni/net.d/10-canal.conflist - 664
/etc/cni/net.d/calico-kubeconfig - 600
Result: Pass
1.4.10 - Ensure that the Container Network Interface file ownership is set to root:root
(Not Scored)
Notes
This is a manual check.
Audit (/var/lib/cni/networks/k8s-pod-network
)
stat -c "%n - %U:%G" /var/lib/cni/networks/k8s-pod-network/*
Returned Value:
/var/lib/cni/networks/k8s-pod-network/10.42.0.2 - root:root
/var/lib/cni/networks/k8s-pod-network/10.42.0.3 - root:root
/var/lib/cni/networks/k8s-pod-network/last_reserved_ip.0 - root:root
/var/lib/cni/networks/k8s-pod-network/lock - root:root
Audit (/etc/cni/net.d
)
stat -c "%n - %U:%G" /etc/cni/net.d/*
Returned Value:
/etc/cni/net.d/10-canal.conflist - root:root
/etc/cni/net.d/calico-kubeconfig - root:root
Result: Pass
1.4.11 - Ensure that the etcd data directory permissions are set to 700
or more restrictive (Scored)
Notes
Files underneath the data dir have permissions set to 700
stat -c "%n - %a" /var/lib/rancher/etcd/*
/var/lib/etcd/member - 700
Audit
stat -c %a /var/lib/rancher/etcd
Returned Value: 700
Result: Pass
1.4.12 - Ensure that the etcd
data directory ownership is set to etcd:etcd
(Scored)
Notes
The etcd
container runs as the etcd
user. The data directory and files are owned by etcd
.
Audit
stat -c %U:%G /var/lib/rancher/etcd
Returned Value: etcd:etcd
Result: Pass
1.4.13 - Ensure that the file permissions for admin.conf
are set to 644
or more restrictive (Scored)
Notes
RKE does not store the kubernetes default kubeconfig credentials file on the nodes. It’s presented to user where RKE is run. We recommend that this kube_config_cluster.yml file be kept in secure store.
Result: Not Applicable
1.4.14 - Ensure that ownership of admin.conf
is set to root:root
(Scored)
Notes
RKE does not store the default kubectl
config credentials file on the nodes. It presents credentials to the user when rke
is first run, and only on the device where the user ran the command. Rancher Labs recommends that this kube_config_cluster.yml
file be kept in secure store.
Result: Not Applicable
1.4.15 - Ensure that the file permissions for scheduler.conf
are set to 644
or more restrictive (Scored)
Audit
stat -c %a /etc/kubernetes/ssl/kubecfg-kube-scheduler.yaml
Returned Value: 644
Result: Pass
1.4.16 - Ensure that the file ownership of scheduler.conf
is set to root:root
(Scored)
Audit
stat -c %U:%G /etc/kubernetes/ssl/kubecfg-kube-scheduler.yaml
Returned Value: root:root
Result: Pass
1.4.17 - Ensure that the file permissions for controller-manager.conf
are set to 644
or more restrictive (Scored)
Audit
stat -c %a /etc/kubernetes/ssl/kubecfg-kube-controller-manager.yaml
Returned Value: 644
Result: Pass
1.4.18 - Ensure that the file ownership of controller-manager.conf
is set to root:root
(Scored)
Audit
stat -c %U:%G /etc/kubernetes/ssl/kubecfg-kube-controller-manager.yaml
Returned Value: root:root
Result: Pass
1.4.19 - Ensure that the Kubernetes PKI directory and file ownership is set to root:root (Scored)
Audit
ls -laR /etc/kubernetes/ssl/ |grep -v yaml
Returned Value:
total 128
drwxr-xr-x 2 root root 4096 Jul 1 19:53 .
drwxr-xr-x 4 root root 4096 Jul 1 19:53 ..
-rw------- 1 root root 1679 Jul 1 19:53 kube-apiserver-key.pem
-rw------- 1 root root 1679 Jul 1 19:53 kube-apiserver-proxy-client-key.pem
-rw-r--r-- 1 root root 1107 Jul 1 19:53 kube-apiserver-proxy-client.pem
-rw------- 1 root root 1675 Jul 1 19:53 kube-apiserver-requestheader-ca-key.pem
-rw-r--r-- 1 root root 1082 Jul 1 19:53 kube-apiserver-requestheader-ca.pem
-rw-r--r-- 1 root root 1285 Jul 1 19:53 kube-apiserver.pem
-rw------- 1 root root 1675 Jul 1 19:53 kube-ca-key.pem
-rw-r--r-- 1 root root 1017 Jul 1 19:53 kube-ca.pem
-rw------- 1 root root 1679 Jul 1 19:53 kube-controller-manager-key.pem
-rw-r--r-- 1 root root 1062 Jul 1 19:53 kube-controller-manager.pem
-rw------- 1 root root 1675 Jul 1 19:53 kube-etcd-172-31-16-161-key.pem
-rw-r--r-- 1 root root 1277 Jul 1 19:53 kube-etcd-172-31-16-161.pem
-rw------- 1 root root 1679 Jul 1 19:53 kube-etcd-172-31-24-134-key.pem
-rw-r--r-- 1 root root 1277 Jul 1 19:53 kube-etcd-172-31-24-134.pem
-rw------- 1 root root 1675 Jul 1 19:53 kube-etcd-172-31-30-57-key.pem
-rw-r--r-- 1 root root 1277 Jul 1 19:53 kube-etcd-172-31-30-57.pem
-rw------- 1 root root 1679 Jul 1 19:53 kube-node-key.pem
-rw-r--r-- 1 root root 1070 Jul 1 19:53 kube-node.pem
-rw------- 1 root root 1679 Jul 1 19:53 kube-proxy-key.pem
-rw-r--r-- 1 root root 1046 Jul 1 19:53 kube-proxy.pem
-rw------- 1 root root 1679 Jul 1 19:53 kube-scheduler-key.pem
-rw-r--r-- 1 root root 1050 Jul 1 19:53 kube-scheduler.pem
-rw------- 1 root root 1679 Jul 1 19:53 kube-service-account-token-key.pem
-rw-r--r-- 1 root root 1285 Jul 1 19:53 kube-service-account-token.pem
Result: Pass
1.4.20 - Ensure that the Kubernetes PKI certificate file permissions are set to 644
or more restrictive (Scored)
Audit
stat -c "%n - %a" /etc/kubernetes/ssl/*.pem |grep -v key
Returned Value:
/etc/kubernetes/ssl/kube-apiserver-proxy-client.pem - 644
/etc/kubernetes/ssl/kube-apiserver-requestheader-ca.pem - 644
/etc/kubernetes/ssl/kube-apiserver.pem - 644
/etc/kubernetes/ssl/kube-ca.pem - 644
/etc/kubernetes/ssl/kube-controller-manager.pem - 644
/etc/kubernetes/ssl/kube-etcd-172-31-16-161.pem - 644
/etc/kubernetes/ssl/kube-etcd-172-31-24-134.pem - 644
/etc/kubernetes/ssl/kube-etcd-172-31-30-57.pem - 644
/etc/kubernetes/ssl/kube-node.pem - 644
/etc/kubernetes/ssl/kube-proxy.pem - 644
/etc/kubernetes/ssl/kube-scheduler.pem - 644
/etc/kubernetes/ssl/kube-service-account-token.pem - 644
Result: Pass
1.4.21 - Ensure that the Kubernetes PKI key file permissions are set to 600 (Scored)
Audit
stat -c "%n - %a" /etc/kubernetes/ssl/*key*
Returned Value:
/etc/kubernetes/ssl/kube-apiserver-key.pem - 600
/etc/kubernetes/ssl/kube-apiserver-proxy-client-key.pem - 600
/etc/kubernetes/ssl/kube-apiserver-requestheader-ca-key.pem - 600
/etc/kubernetes/ssl/kube-ca-key.pem - 600
/etc/kubernetes/ssl/kube-controller-manager-key.pem - 600
/etc/kubernetes/ssl/kube-etcd-172-31-16-161-key.pem - 600
/etc/kubernetes/ssl/kube-etcd-172-31-24-134-key.pem - 600
/etc/kubernetes/ssl/kube-etcd-172-31-30-57-key.pem - 600
/etc/kubernetes/ssl/kube-node-key.pem - 600
/etc/kubernetes/ssl/kube-proxy-key.pem - 600
/etc/kubernetes/ssl/kube-scheduler-key.pem - 600
/etc/kubernetes/ssl/kube-service-account-token-key.pem - 600
Result: Pass
1.5 - etcd
1.5.1 - Ensure that the --cert-file
and --key-file
arguments are set as appropriate (Scored)
Audit (--cert-file
)
docker inspect etcd | jq -e '.[0].Args[] | match("--cert-file=.*").string'
Note Certificate file name may vary slightly, since it contains the IP of the etcd container.
Returned Value: --cert-file=/etc/kubernetes/ssl/kube-etcd-172-31-24-134.pem
Audit (--key-file
)
docker inspect etcd | jq -e '.[0].Args[] | match("--key-file=.*").string'
Note Key file name may vary slightly, since it contains the IP of the etcd container.
Returned Value: --key-file=/etc/kubernetes/ssl/kube-etcd-172-31-24-134-key.pem
Result: Pass
1.5.2 - Ensure that the --client-cert-auth
argument is set to true
(Scored)
Notes
Setting “–client-cert-auth” is the equivalent of setting “–client-cert-auth=true”.
Audit
docker inspect etcd | jq -e '.[0].Args[] | match("--client-cert-auth(=true)*").string'
Returned Value: --client-cert-auth
Result: Pass
1.5.3 - Ensure that the --auto-tls
argument is not set to true
(Scored)
Audit
docker inspect etcd | jq -e '.[0].Args[] | match("--auto-tls(?:(?!=false).*)").string'
Returned Value: null
Result: Pass
1.5.4 - Ensure that the --peer-cert-file
and --peer-key-file
arguments are set as appropriate (Scored)
Audit (--peer-cert-file
)
docker inspect etcd | jq -e '.[0].Args[] | match("--peer-cert-file=.*").string'
Note Certificate file name may vary slightly, since it contains the IP of the etcd container.
Returned Value: --peer-cert-file=/etc/kubernetes/ssl/kube-etcd-172-31-22-135.pem
Audit (--peer-key-file
)
docker inspect etcd | jq -e '.[0].Args[] | match("--peer-key-file=.*").string'
Note Key file name may vary slightly, since it contains the IP of the etcd container.
Returned Value: --peer-key-file=/etc/kubernetes/ssl/kube-etcd-172-31-22-135-key.pem
Result: Pass
1.5.5 - Ensure that the --peer-client-cert-auth
argument is set to true
(Scored)
Notes
Setting --peer-client-cert-auth
is the equivalent of setting --peer-client-cert-auth=true
.
Audit
docker inspect etcd | jq -e '.[0].Args[] | match("--peer-client-cert-auth(=true)*").string'
Returned Value: --peer-client-cert-auth
Result: Pass
1.5.6 - Ensure that the --peer-auto-tls
argument is not set to true
(Scored)
Audit
docker inspect etcd | jq -e '.[0].Args[] | match("--peer-auto-tls(?:(?!=false).*)").string'
Returned Value: null
Result: Pass
1.5.7 - Ensure that a unique Certificate Authority is used for etcd
(Not Scored)
Mitigation
RKE supports connecting to an external etcd cluster. This external cluster could be configured with its own discreet CA.
Notes
--trusted-ca-file
is set and different from the --client-ca-file
used by kube-apiserver
.
Audit
docker inspect etcd | jq -e '.[0].Args[] | match("--trusted-ca-file=(?:(?!/etc/kubernetes/ssl/kube-ca.pem).*)").string'
Returned Value: null
Result: Pass (See Mitigation)
1.6 - General Security Primitives
These “Not Scored” controls are implementation best practices. To ease the administrative burden, we recommend that you implement these best practices on your workload clusters by creating clusters with Rancher rather than using RKE alone.
1.6.1 - Ensure that the cluster-admin role is only used where required (Not Scored)
Rancher has built in support for maintaining and enforcing Kubernetes RBAC on your workload clusters.
Rancher has the ability integrate with external authentication sources (LDAP, SAML, AD…) allows easy access with unique credentials to your existing users or groups.
1.6.2 - Create administrative boundaries between resources using namespaces (Not Scored)
With Rancher, users or groups can be assigned access to all clusters, a single cluster or a “Project” (a group of one or more namespaces in a cluster). This allows granular access control to cluster resources.
1.6.3 - Create network segmentation using Network Policies (Not Scored)
Rancher can (optionally) automatically create Network Policies to isolate “Projects” (a group of one or more namespaces) in a cluster.
See “Cluster Options” when creating a cluster with Rancher to turn on Network Isolation.
1.6.4 - Ensure that the seccomp
profile is set to docker/default
in your pod definitions (Not Scored)
Since this requires the enabling of AllAlpha feature gates we would not recommend enabling this feature at the moment.
1.6.5 - Apply security context to your pods and containers (Not Scored)
This practice does go against control 1.1.13, but we prefer using a PodSecurityPolicy and allowing security context to be set over a blanket deny.
Rancher allows users to set various Security Context options when launching pods via the GUI interface.
1.6.6 - Configure image provenance using the ImagePolicyWebhook
admission controller (Not Scored)
Image Policy Webhook requires a 3rd party service to enforce policy. This can be configured in the --admission-control-config-file
. See the Host configuration section for the admission.yaml file.
1.6.7 - Configure network policies as appropriate (Not Scored)
Rancher can (optionally) automatically create Network Policies to isolate projects (a group of one or more namespaces) within a cluster.
See the Cluster Options section when creating a cluster with Rancher to turn on network isolation.
1.6.8 - Place compensating controls in the form of PodSecurityPolicy (PSP) and RBAC for privileged container usage (Not Scored)
Section 1.7 of this guide shows how to add and configure a default “restricted” PSP based on controls.
With Rancher you can create a centrally maintained “restricted” PSP and deploy it to all of the clusters that Rancher manages.
1.7 - Pod Security Policies (PSP)
This RKE configuration has two Pod Security Policies.
default-psp
: assigned to namespaces that require additional privileged access:kube-system
,ingress-nginx
andcattle-system
.restricted
: This is the cluster default PSP and follows the best practices defined by controls in this section.
1.7.1 - Do not admit privileged containers (Not Scored)
Notes
The restricted PodSecurityPolicy is available to all ServiceAccounts.
Audit
kubectl get psp restricted -o jsonpath='{.spec.privileged}' | grep "true"
Returned Value: null
Result: Pass
1.7.2 - Do not admit containers wishing to share the host process ID namespace (Scored)
Notes
The restricted PodSecurityPolicy is available to all ServiceAccounts.
Audit
kubectl get psp restricted -o jsonpath='{.spec.hostPID}' | grep "true"
Returned Value: null
Result: Pass
1.7.3 - Do not admit containers wishing to share the host IPC namespace (Scored)
Notes
The restricted PodSecurityPolicy is available to all ServiceAccounts.
Audit
kubectl get psp restricted -o jsonpath='{.spec.hostIPC}' | grep "true"
Returned Value: null
Result: Pass
1.7.4 - Do not admit containers wishing to share the host network namespace (Scored)
Notes
The restricted PodSecurityPolicy is available to all ServiceAccounts.
Audit
kubectl get psp restricted -o jsonpath='{.spec.hostNetwork}' | grep "true"
Returned Value: null
Result: Pass
1.7.5 - Do not admit containers with allowPrivilegeEscalation
(Scored)
Notes
The restricted PodSecurityPolicy is available to all ServiceAccounts.
Audit
kubectl get psp restricted -o jsonpath='{.spec.allowPrivilegeEscalation}' | grep "true"
Returned Value: null
Result: Pass
1.7.6 - Do not admit containers whose processes run as root
(Not Scored)
Notes
The restricted PodSecurityPolicy is available to all ServiceAccounts.
Audit
kubectl get psp restricted -o jsonpath='{.spec.runAsUser.rule}' | grep "RunAsAny"
Returned Value: null
Result: Pass
1.7.7 - Do not admit containers with dangerous capabilities (Not Scored)
Notes
The restricted PodSecurityPolicy is available to all ServiceAccounts.
Audit
kubectl get psp restricted -o jsonpath='{.spec.requiredDropCapabilities}' | grep "NET_RAW"
Returned Value: [NET_RAW]
Result: Pass
2 - Worker Node Security Configuration
2.1 - Kubelet
2.1.1 - Ensure that the --anonymous-auth
argument is set to false
(Scored)
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--anonymous-auth=false").string'
Returned Value: --anonymous-auth=false
Result: Pass
2.1.2 - Ensure that the --authorization-mode
argument is not set to AlwaysAllow
(Scored)
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--authorization-mode=Webhook").string'
Returned Value: --authorization-mode=Webhook
Result: Pass
2.1.3 - Ensure that the --client-ca-file
argument is set as appropriate (Scored)
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--client-ca-file=.*").string'
Returned Value: --client-ca-file=/etc/kubernetes/ssl/kube-ca.pem
Result: Pass
2.1.4 - Ensure that the --read-only-port
argument is set to 0
(Scored)
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--read-only-port=0").string'
Returned Value: --read-only-port=0
Result: Pass
2.1.5 - Ensure that the --streaming-connection-idle-timeout
argument is not set to 0
(Scored)
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--streaming-connection-idle-timeout=.*").string'
Returned Value: --streaming-connection-idle-timeout=1800s
Result: Pass
2.1.6 - Ensure that the --protect-kernel-defaults
argument is set to true
(Scored)
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--protect-kernel-defaults=true").string'
Returned Value: --protect-kernel-defaults=true
Result: Pass
2.1.7 - Ensure that the --make-iptables-util-chains
argument is set to true
(Scored)
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--make-iptables-util-chains=true").string'
Returned Value: --make-iptables-util-chains=true
Result: Pass
2.1.8 - Ensure that the --hostname-override
argument is not set (Scored)
Notes This is used by most cloud providers. Not setting this is not practical in most cases.
Result: Not Applicable
2.1.9 - Ensure that the --event-qps
argument is set to 0
(Scored)
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--event-qps=0").string'
Returned Value: --event-qps=0
Result: Pass
2.1.10 - Ensure that the --tls-cert-file
and --tls-private-key-file
arguments are set as appropriate (Scored)
Notes
RKE does not set these options and uses the kubelet’s self generated certificates for TLS communication. These files are located in the default directory (/var/lib/kubelet/pki
).
Audit (--tls-cert-file
)
docker inspect kubelet | jq -e '.[0].Args[] | match("--tls-cert-file=.*").string'
Returned Value: null
Audit (--tls-private-key-file
)
docker inspect kubelet | jq -e '.[0].Args[] | match("--tls-private-key-file=.*").string'
Returned Value: null
Result: Pass
2.1.11 - Ensure that the --cadvisor-port
argument is set to 0
(Scored)
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--cadvisor-port=0").string'
Returned Value: null
Result: Pass
2.1.12 - Ensure that the --rotate-certificates
argument is not set to false
(Scored)
Notes
RKE handles certificate rotation through an external process.
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--rotate-certificates=true").string'
Returned Value: null
Result: Not Applicable
2.1.13 - Ensure that the RotateKubeletServerCertificate
argument is set to true
(Scored)
Notes
RKE handles certificate rotation through an external process.
Result: Not Applicable
2.1.14 - Ensure that the kubelet only makes use of strong cryptographic ciphers (Not Scored)
Audit (Allowed Ciphers)
docker inspect kubelet | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256).*").captures[].string'
Returned Value: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256).*").captures[].string'
Returned Value: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305).*").captures[].string'
Returned Value: TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384).*").captures[].string'
Returned Value: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305).*").captures[].string'
Returned Value: TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384).*").captures[].string'
Returned Value: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_RSA_WITH_AES_256_GCM_SHA384).*").captures[].string'
Returned Value: TLS_RSA_WITH_AES_256_GCM_SHA384
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(TLS_RSA_WITH_AES_128_GCM_SHA256).*").captures[].string'
Returned Value: TLS_RSA_WITH_AES_128_GCM_SHA256
Audit (Disallowed Ciphers)
docker inspect kubelet | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(CBC).*").captures[].string'
Returned Value: null
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--tls-cipher-suites=.*(RC4).*").captures[].string'
Returned Value: null
Result: Pass
2.2 - Configuration Files
2.2.1 - Ensure that the permissions for kubelet.conf
are set to 644
or more restrictive (Scored)
Notes
This is the value of the --kubeconfig
option.
Audit
stat -c %a /etc/kubernetes/ssl/kubecfg-kube-node.yaml
Returned Value: 644
Result: Pass
2.2.2 - Ensure that the kubelet.conf file ownership is set to root:root (Scored)
Notes
This is the value of the --kubeconfig
option.
Audit
stat -c %U:%G /etc/kubernetes/ssl/kubecfg-kube-node.yaml
Returned Value: root:root
Result: Pass
2.2.3 - Ensure that the kubelet service file permissions are set to 644
or more restrictive (Scored)
Notes
RKE doesn’t require or maintain a configuration file for kubelet. All configuration is passed in as arguments at container run time.
Result: Not Applicable
2.2.4 - Ensure that the kubelet service file ownership is set to root:root
(Scored)
Notes
RKE doesn’t require or maintain a configuration file for kubelet. All configuration is passed in as arguments at container run time.
Result: Not Applicable
2.2.5 - Ensure that the proxy kubeconfig file permissions are set to 644
or more restrictive (Scored)
Audit
stat -c %a /etc/kubernetes/ssl/kubecfg-kube-proxy.yaml
Returned Value: 644
Result: Pass
2.2.6 - Ensure that the proxy kubeconfig file ownership is set to root:root
(Scored)
Audit
stat -c %U:%G /etc/kubernetes/ssl/kubecfg-kube-proxy.yaml
Returned Value: root:root
Result: Pass
2.2.7 - Ensure that the certificate authorities file permissions are set to 644
or more restrictive (Scored)
Audit
stat -c %a /etc/kubernetes/ssl/kube-ca.pem
Returned Value: 644
Result: Pass
2.2.8 - Ensure that the client certificate authorities file ownership is set to root:root
(Scored)
Audit
stat -c %U:%G /etc/kubernetes/ssl/kube-ca.pem
Returned Value: root:root
Result: Pass
2.2.9 - Ensure that the kubelet configuration file ownership is set to root:root
(Scored)
Notes
RKE doesn’t require or maintain a configuration file for kubelet. All configuration is passed in as arguments at container run time.
Result: Not Applicable
2.2.10 - Ensure that the kubelet configuration file permissions are set to 644
or more restrictive (Scored)
Notes
RKE doesn’t require or maintain a configuration file for kubelet. All configuration is passed in as arguments at container run time.
Result: Not Applicable