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
Protect node metadata and endpoints
- Prevent unauthenticated / unauthorised to api-server (authorization-mode, .. son on)
Minimize use of, and access to, GUI elements
Verify platform binaries before deploying
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
System Hardening – 15%
Minimize host OS footprint (reduce attack surface)
-
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
-
📚 "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
-
📹 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)
-
🔬 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/
Supply Chain Security – 20%
Minimize base image footprint
-
7 best practices for build containers.
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
-
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
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
Other links :
-
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.
