28 November 2024
Drawing upon our extensive Cloud security expertise, we've put together a set of helpful articles covering security best practices we think are really important on different subjects. In today's article, we will introduce five best practices for network security in your cluster Kubernetes.
Why do I need to secure network communications in Kubernetes ?
You need to secure network communications in Kubernetes to keep your data safe, protect your information, and keep your system secure. It's about safeguarding your data and keeping your Kubernetes setup trustworthy.
What are the five best practices to secure Kubernetes network?
The best thing you can do to secure your Kubernetes network is to implement network policies. Then, you must enable TLS communication between Kubernetes components and between your pods. You should secure your ingress and egress traffic using WAFs and your ingress controller.
Finally, you should use security solutions to add policy networks like Calico. The namespace separation can help configure the above solution, but it doesn’t secure anything by itself.
I use network policies in my cluster
Recommendation: Configure network policies to control communications.
Define and enforce rules that control network traffic between pods. Allow only necessary communication between pods. Policies must also be reviewed and updated to adapt to changing application requirements.
Risks Addressed: Kubernetes network policies allow you to set precise rules for controlling traffic between pods. By enforcing only necessary communication, you reduce the attack surface and mitigate the risk of an attacker's lateral movement within the cluster.
Regularly reviewing and updating policies helps you adapt to changing application requirements and stay ahead of potential vulnerabilities.
I enable Transport Layer Security (TLS) for communication with cluster elements
Recommendation: Enable encryption between your communications.
Enable TLS for secure communication between components in your Kubernetes cluster, such as the API server, etcd, and kubelet. The Kube API, especially, must not be exposed and protected by an additional protection layer such as whitelisting or a bastion.
You should also use Kubernetes Secrets to securely store and manage TLS certificates and keys for your ingresses. Finally, TLS certificates should be regularly rotated to minimize the impact of potential breaches.
Risks Addressed: TLS encryption ensures that data in transit is protected from man-in-the-middle attacks like eavesdropping and tampering. You safeguard sensitive information by using Kubernetes Secrets to manage certificates and keys.
Regularly rotating certificates reduces the risk associated with compromised keys or certificates, minimizing the impact of potential security breaches.
I enable Pod-to-Pod encryption
Recommendation: Enable mTLS encryption between your pods.
Utilize Kubernetes features like mTLS (mutual Transport Layer Security), Linkerd (recommended), and Service Mesh (e.g., Istio or Cilium) to enable encryption for communication between pods. Ensure that communication between pods is encrypted by default to protect data in transit.
Monitor encryption's performance impact to make adjustments as needed. Monitoring is also an excellent practice for detecting threats.
Risks Addressed: Enabling pod-to-pod encryption is vital for protecting data in transit within your Kubernetes cluster. Features like mTLS and Service Mesh offer robust encryption capabilities that protect against man-in-the-middle attacks, a common threat in Kubernetes clusters.
I have secure ingress and egress traffic
Recommendation: Configure upstream protection for your ingress and egress traffic.
Use Kubernetes Ingress controllers to secure incoming traffic to your applications. Implement Web Application Firewalls (WAF) or security services like AWS WAF or Google Cloud Armor to protect against web-based attacks. Utilize egress network policies to control outgoing traffic and prevent unauthorized access to external resources.
Risks Addressed: Securing ingress traffic is crucial for protecting your web applications from attacks. When feasible, securing egress traffic can help prevent data exfiltration, though it is often challenging to implement.
Ingress control can also assist in filtering which users can access your environment, for instance, through IP whitelisting. This is usually handled at the infrastructure level containing Kubernetes rather than within the cluster.
I use network security solutions for Kubernetes
Recommendation: Use more advanced features to increase the protection of your network.
To enhance network security, implement third-party network security solutions and tools, such as Calico, Cilium, or Network Policy Controller. These tools can provide network protection at Layer 7, utilizing identity rather than pod IPs for enhanced security.
Risks Addressed: Third-party network security solutions and advanced policies extend beyond Kubernetes' native security controls, offering additional layers of protection, threat detection, and monitoring. They enable deeper protection within a zero-trust framework while also providing a more maintainable solution.
Conclusion
By following the best practices presented in this article, you can significantly reduce the risk of Kubernetes cluster compromission and improve the overall security of your infrastructure.