CKS Exam Dumps : Certified Kubernetes Security Specialist (CKS)

root# netstat -ltnup

Active Internet connections (only servers)

Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name

tcp 0 0 127.0.0.1:17600 0.0.0.0:* LISTEN 1293/dropbox

tcp 0 0 127.0.0.1:17603 0.0.0.0:* LISTEN 1293/dropbox

tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 575/sshd

tcp 0 0 127.0.0.1:9393 0.0.0.0:* LISTEN 900/perl

tcp 0 0 :::80 :::* LISTEN 9583/docker-proxy

tcp 0 0 :::443 :::* LISTEN 9571/docker-proxy

udp 0 0 0.0.0.0:68 0.0.0.0:* 8822/dhcpcd

root# netstat -ltnup | grep ':22'

tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 575/sshd

The ss command is the replacement of the netstat command.

Now let’s see how to use the ss command to see which process is listening on port 22:

root# ss -ltnup 'sport = :22'

Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port

tcp LISTEN 0 128 0.0.0.0:22 0.0.0.0:* users:("sshd",pid=575,fd=3))

Fix all of the following violations that were found against the API server:-

 a. Ensure that the RotateKubeletServerCertificate argument is set to true.

apiVersion: v1

kind: Pod

metadata:

creationTimestamp: null

labels:

component: kubelet

tier: control-plane

name: kubelet

namespace: kube-system

spec:

containers:

- command:

- kube-controller-manager

+ - --feature-gates=RotateKubeletServerCertificate=true

image: gcr.io/google_containers/kubelet-amd64:v1.6.0

livenessProbe:

failureThreshold: 8

httpGet:

host: 127.0.0.1

path: /healthz

port: 6443

scheme: HTTPS

initialDelaySeconds: 15

timeoutSeconds: 15

name: kubelet

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

  b. Ensure that the admission control plugin PodSecurityPolicy is set.

audit: "/bin/ps -ef | grep $apiserverbin | grep -v grep"

tests:

test_items:

- flag: "--enable-admission-plugins"

compare:

op: has

value: "PodSecurityPolicy"

set: true

remediation: |

Follow the documentation and create Pod Security Policy objects as per your environment.

Then, edit the API server pod specification file $apiserverconf

on the master node and set the --enable-admission-plugins parameter to a

value that includes PodSecurityPolicy :

--enable-admission-plugins=...,PodSecurityPolicy,...

Then restart the API Server.

scored: true

c. Ensure that the --kubelet-certificate-authority argument is set as appropriate.

audit: "/bin/ps -ef | grep $apiserverbin | grep -v grep"

tests:

test_items:

- flag: "--kubelet-certificate-authority"

set: true

remediation: |

Follow the Kubernetes documentation and setup the TLS connection between the

apiserver and kubelets. Then, edit the API server pod specification file

$apiserverconf on the master node and set the --kubelet-certificate-authority

parameter to the path to the cert file for the certificate authority.

--kubelet-certificate-authority=

scored: true

Fix all of the following violations that were found against the ETCD:-

a. Ensure that the --auto-tls argument is not set to true

Edit the etcd pod specification file $etcdconf on the master

node and either remove the --auto-tls parameter or set it to false.

--auto-tls=false

b. Ensure that the --peer-auto-tls argument is not set to true

Edit the etcd pod specification file $etcdconf on the master

node and either remove the --peer-auto-tls parameter or set it to false.

--peer-auto-tls=false