YunShiHang/certified-kubernetes-security-specialist

References for CKS Exam Objectives - Certified Kubernetes Security Specialist

Cluster Setup – 10%

Use Network security policies to restrict cluster level access

• https://kubernetes.io/docs/concepts/services-networking/network-policies/
• 🔬 https://github.com/ahmetb/kubernetes-network-policy-recipes
• https://medium.com/@reuvenharrison/an-introduction-to-kubernetes-network-policies-for-security-people-ba92dd4c809d
• https://github.com/Tufin/test-network-policies

Use CIS benchmark to review the security configuration of Kubernetes components (etcd, kubelet, kubedns, kubeapi)

# install kube-bench in the current host dir
docker run --rm -it -v `pwd`:/host aquasec/kube-bench:latest install

# benchmarking your cluster ( verify the curren kubeconfig before)
./kube-bench <name-of-node>

• https://www.cisecurity.org/benchmark/kubernetes/
• https://github.com/dev-sec/cis-kubernetes-benchmark
• https://github.com/aquasecurity/kube-bench
• https://cloud.google.com/kubernetes-engine/docs/concepts/cis-benchmarks

Properly set up Ingress objects with security control

• secure an Ingress by specifying a Secret that contains a TLS private key and certificate

Protect node metadata and endpoints

• Prevent unauthenticated / unauthorised to api-server (authorization-mode, .. son on)

Minimize use of, and access to, GUI elements

• https://blog.heptio.com/on-securing-the-kubernetes-dashboard-16b09b1b7aca

Verify platform binaries before deploying

• https://github.com/kubernetes/kubernetes/releases

Cluster Hardening – 15%

Restrict access to Kubernetes API

• Controlling Access to the Kubernetes API : https://kubernetes.io/docs/reference/access-authn-authz/controlling-access/

Use Role Based Access Controls to minimize exposure

• https://kubernetes.io/docs/reference/access-authn-authz/rbac/
• https://github.com/David-VTUK/CKA-StudyGuide/blob/master/RevisionTopics/Part-5-Security.md

Exercise caution in using service accounts e.g. disable defaults, minimize permissions on newly created ones

• https://kubernetes.io/docs/reference/access-authn-authz/service-accounts-admin/
• https://kubernetes.io/docs/tasks/configure-pod-container/configure-service-account/

Update Kubernetes frequently

• https://kubernetes.io/docs/tasks/administer-cluster/kubeadm/kubeadm-upgrade/

System Hardening – 15%

Minimize host OS footprint (reduce attack surface)

• CIS benchmark Overview/General

• CIS benchmark dedicated for each distribution

• https://www.cisecurity.org/benchmark/red_hat_linux/
• https://www.cisecurity.org/benchmark/ubuntu_linux/
• https://www.cisecurity.org/benchmark/centos_linux/
• https://www.cisecurity.org/benchmark/debian_linux/
• https://www.cisecurity.org/benchmark/suse_linux/
• https://www.cisecurity.org/benchmark/oracle_linux/

Minimize IAM roles

• Least privilege pincipal is generally the way to go!

Minimize external access to the network

• ACL at the level of subnet : https://docs.aws.amazon.com/vpc/latest/userguide/vpc-network-acls.html
• Security Group at the level of machine : https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-security-groups.html
• Firewall at the level of OS ( ufw, firewall-cmd ) : https://www.linode.com/docs/security/firewalls/configure-firewall-with-ufw/

Appropriately use kernel hardening tools such as AppArmor, seccomp

• https://kubernetes.io/docs/tutorials/clusters/apparmor/

• https://kubernetes.io/docs/tutorials/clusters/seccomp/

• 📚 "Container Security" by Liz Rice which covers AppArmor, Seccomp, SELinux and the whole gang.

Minimize Microservice Vulnerabilities – 20%

Setup appropriate OS level security domains e.g. using PSP, OPA, security contexts

• PSP : https://kubernetes.io/docs/concepts/policy/pod-security-policy/

• OPA : https://www.openpolicyagent.org/docs/latest/kubernetes-primer/

• Security Context : https://kubernetes.io/docs/tasks/configure-pod-container/security-context/

Manage Kubernetes secrets

• https://kubernetes.io/docs/concepts/configuration/secret/

• 📹 TGIK - Advanced k8s secret management : https://www.youtube.com/watch?v=IznsHhKL428&ab_channel=VMwareCloudNativeApps

• 🔬 Sealed Secrets : https://github.com/bitnami-labs/sealed-secrets

• secrets-store-csi-driver : https://github.com/kubernetes-sigs/secrets-store-csi-driver

Use container runtime sandboxes in multi-tenant environments (e.g. gvisor, kata containers)

• gVisor : https://gvisor.dev/docs/user_guide/install/

• kata : https://github.com/kata-containers/kata-containers

• 🔬 Hands-on Kata : https://github.com/abdennour/abdennour.github.io/blob/master/_posts/2018-06-09-successfully-running-kata-containers-in-the-cloud.markdown

Implement pod to pod encryption by use of mTLS

• https://kubernetes.io/docs/tasks/tls/managing-tls-in-a-cluster/

• Using istio , https://developer.ibm.com/technologies/containers/tutorials/istio-security-mtls/

• Using linkerd, https://linkerd.io/2/features/automatic-mtls/

• 🔬 https://www.istioworkshop.io/11-security/01-mtls/

Supply Chain Security – 20%

Minimize base image footprint

• 7 best practices for build containers.

• https://github.com/GoogleContainerTools/distroless

Secure your supply chain: whitelist allowed registries, sign and validate images

• Docker Way : https://docs.docker.com/engine/security/trust/content_trust/

• Tools for manage supply chain and artifacts:

• tools for siging container image Cryptographically:

• example - restrict pulling images from registries

• Related also with https://kubernetes.io/blog/2019/03/21/a-guide-to-kubernetes-admission-controllers/

Use static analysis of user workloads (e.g.Kubernetes resources, Docker files)

• kubehunter: https://github.com/aquasecurity/kube-hunter
• Tools around static container image scan:

Scan images for known vulnerabilities

• Clair: https://github.com/quay/clair

• Tools around dynamic container image scan :

Monitoring, Logging and Runtime Security – 20%

Perform behavioral analytics of syscall process and file activities at the host and container level to detect malicious activities

• https://kubernetes.io/docs/tutorials/clusters/seccomp/

Detect threats within physical infrastructure, apps, networks, data, users and workloads

Detect all phases of attack regardless where it occurs and how it spreads

• Get the General Concept : https://www.dnvgl.com/article/the-seven-phases-of-a-cyber-attack-118270

Perform deep analytical investigation and identification of bad actors within environment

Ensure immutability of containers at runtime

• Falco might help ?

Use Audit Logs to monitor access

• https://kubernetes.io/docs/tasks/debug-application-cluster/audit/

---

Other links :

• SIG security - MoM

• Firecracker for multi-tenancy, Bottlerocket to reduce the attack surface, audit2rbac for generating RBAC roles

---

Disclaimer

The given links are our assumptions and ideas - we neither have insights into the exam requirements, nor do we know how exactly it will look like. We are guessing about possibilities and try to collect resources.

License

Stargazers over time