Linux Foundation CKS valid exam dumps : Certified Kubernetes Security Specialist (CKS)

Correct Answer:

See the Explanation below
Explanation:

Correct Answer:

See the Explanation below for complete solution
Explanation:
1) SSH to control-plane node
ssh cks000002
sudo -i
2) Edit API Server static pod manifest
API server in kubeadm runs as a static pod.
vi /etc/kubernetes/manifests/kube-apiserver.yaml
3) Apply required API Server security settings
3.1 Forbid anonymous authentication
Find command: section and ensure this line exists:
- --anonymous-auth=false
3.2 Use authorization mode Node,RBAC
Ensure exactly this line exists (and no AlwaysAllow):
- --authorization-mode=Node,RBAC
❌ Remove if present:
- --authorization-mode=AlwaysAllow
3.3 Enable admission controller NodeRestriction
Find --enable-admission-plugins and ensure NodeRestriction is included.
Correct example:
- --enable-admission-plugins=NodeRestriction
If other plugins already exist, append NodeRestriction, e.g.:
- --enable-admission-plugins=NamespaceLifecycle,ServiceAccount,NodeRestriction
4) Save file and let kubelet restart API server
Just save and exit (:wq)
Kubelet will automatically restart the API server pod.
5) Switch kubectl to secured config
Current kubectl will stop working after API server hardening.
export KUBECONFIG=/etc/kubernetes/admin.conf
Verify access:
kubectl get nodes
6) Remove insecure ClusterRoleBinding
Delete system:anonymous binding:
kubectl delete clusterrolebinding system:anonymous
Verify removal:
kubectl get clusterrolebinding | grep anonymous
(no output = correct)
7) Quick validation (optional but fast)
API server flags check:
grep -n "anonymous-auth" /etc/kubernetes/manifests/kube-apiserver.yaml
grep -n "authorization-mode" /etc/kubernetes/manifests/kube-apiserver.yaml grep -n "NodeRestriction" /etc/kubernetes/manifests/kube-apiserver.yaml

Correct Answer:

See the Explanation below for complete solution
Explanation:
1) Connect to the correct host
ssh cks000032
sudo -i
2) Use admin kubeconfig
export KUBECONFIG=/etc/kubernetes/admin.conf
3) Verify prerequisites (quick check)
These should already exist per task.
kubectl -n prod get svc web
kubectl -n prod get secret web-cert
kubectl get pods -n ingress-nginx
(If the ingress controller pods exist, you're good.)
4) Create the Ingress resource
Create Ingress named web in namespace prod with:
host: web.k8s.local
all paths → Service web
TLS using Secret web-cert
HTTP → HTTPS redirect (NGINX)
cat <<EOF | kubectl apply -f -
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: web
namespace: prod
annotations:
nginx.ingress.kubernetes.io/ssl-redirect: "true"
nginx.ingress.kubernetes.io/force-ssl-redirect: "true"
spec:
ingressClassName: nginx
tls:
- hosts:
- web.k8s.local
secretName: web-cert
rules:
- host: web.k8s.local
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: web
port:
number: 80
EOF
5) Verify Ingress creation
kubectl -n prod get ingress web
kubectl -n prod describe ingress web
Confirm:
Host = web.k8s.local
TLS Secret = web-cert
Backend Service = web
6) Test HTTP → HTTPS redirect
curl -L http://web.k8s.local
Expected:
Redirects to https://web.k8s.local
Returns application response over HTTPS

Correct Answer:

API server:
Ensure the --authorization-mode argument includes RBAC
Turn on Role Based Access Control.
Role Based Access Control (RBAC) allows fine-grained control over the operations that different entities can perform on different objects in the cluster. It is recommended to use the RBAC authorization mode.
Fix - Buildtime
Kubernetes
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
labels:
component: kube-apiserver
tier: control-plane
name: kube-apiserver
namespace: kube-system
spec:
containers:
- command:
+ - kube-apiserver
+ - --authorization-mode=RBAC,Node
image: gcr.io/google_containers/kube-apiserver-amd64:v1.6.0
livenessProbe:
failureThreshold: 8
httpGet:
host: 127.0.0.1
path: /healthz
port: 6443
scheme: HTTPS
initialDelaySeconds: 15
timeoutSeconds: 15
name: kube-apiserver-should-pass
resources:
requests:
cpu: 250m
volumeMounts:
- mountPath: /etc/kubernetes/
name: k8s
readOnly: true
- mountPath: /etc/ssl/certs
name: certs
- mountPath: /etc/pki
name: pki
hostNetwork: true
volumes:
- hostPath:
path: /etc/kubernetes
name: k8s
- hostPath:
path: /etc/ssl/certs
name: certs
- hostPath:
path: /etc/pki
name: pki
Ensure the --authorization-mode argument includes Node
Remediation: Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the master node and set the --authorization-mode parameter to a value that includes Node.
--authorization-mode=Node,RBAC
Audit:
/bin/ps -ef | grep kube-apiserver | grep -v grep
Expected result:
'Node,RBAC' has 'Node'
Ensure that the --profiling argument is set to false
Remediation: Edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the master node and set the below parameter.
--profiling=false
Audit:
/bin/ps -ef | grep kube-apiserver | grep -v grep
Expected result:
'false' is equal to 'false'
Fix all of the following violations that were found against the Kubelet:- Ensure the --anonymous-auth argument is set to false.
Remediation: If using a Kubelet config file, edit the file to set authentication: anonymous: enabled to false. If using executable arguments, edit the kubelet service file /etc/systemd/system/kubelet.service.d/10-kubeadm.conf on each worker node and set the below parameter in KUBELET_SYSTEM_PODS_ARGS variable.
--anonymous-auth=false
Based on your system, restart the kubelet service. For example:
systemctl daemon-reload
systemctl restart kubelet.service
Audit:
/bin/ps -fC kubelet
Audit Config:
/bin/cat /var/lib/kubelet/config.yaml
Expected result:
'false' is equal to 'false'
2) Ensure that the --authorization-mode argument is set to Webhook.
Audit
docker inspect kubelet | jq -e '.[0].Args[] | match("--authorization-mode=Webhook").string' Returned Value: --authorization-mode=Webhook Fix all of the following violations that were found against the ETCD:- a. Ensure that the --auto-tls argument is not set to true Do not use self-signed certificates for TLS. etcd is a highly-available key value store used by Kubernetes deployments for persistent storage of all of its REST API objects. These objects are sensitive in nature and should not be available to unauthenticated clients. You should enable the client authentication via valid certificates to secure the access to the etcd service.
Fix - Buildtime
Kubernetes
apiVersion: v1
kind: Pod
metadata:
annotations:
scheduler.alpha.kubernetes.io/critical-pod: ""
creationTimestamp: null
labels:
component: etcd
tier: control-plane
name: etcd
namespace: kube-system
spec:
containers:
- command:
+ - etcd
+ - --auto-tls=true
image: k8s.gcr.io/etcd-amd64:3.2.18
imagePullPolicy: IfNotPresent
livenessProbe:
exec:
command:
- /bin/sh
- -ec
- ETCDCTL_API=3 etcdctl --endpoints=https://[192.168.22.9]:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt
--cert=/etc/kubernetes/pki/etcd/healthcheck-client.crt --key=/etc/kubernetes/pki/etcd/healthcheck-client.key get foo failureThreshold: 8 initialDelaySeconds: 15 timeoutSeconds: 15 name: etcd-should-fail resources: {} volumeMounts:
- mountPath: /var/lib/etcd
name: etcd-data
- mountPath: /etc/kubernetes/pki/etcd
name: etcd-certs
hostNetwork: true
priorityClassName: system-cluster-critical
volumes:
- hostPath:
path: /var/lib/etcd
type: DirectoryOrCreate
name: etcd-data
- hostPath:
path: /etc/kubernetes/pki/etcd
type: DirectoryOrCreate
name: etcd-certs
status: {}

Correct Answer:

See the Explanation below
Explanation: