Kubernetes (K8S) has revolutionized software development, but managing such a complex system with numerous components can be challenging. Fortunately, there are several best practices your team can adopt to secure your K8S environment and reduce your attack surface. By implementing these Kubernetes security best practices, you'll not only enhance your cybersecurity defenses but also improve various other business processes.

1. Adopt a Zero Trust Architecture
Kubernetes systems contain a large number of clusters and nodes, all of which can talk to each other. That makes it easy for attackers to move laterally across your network and cause damage, so it's simply too dangerous to assume an access request is authorized just because it's already on the inside.

Zero Trust architecture employ a "never trust, always verify" approach to network validation, and they're essential for securing Kubernetes platforms.

2. Implement Least Privilege Access
Zero Trust architecture uses the least privilege principle to assess the legitimacy of access requests. This principle grants your users the bare minimum amount of access that they need to perform their tasks, preventing them from accessing unauthorized resources.

To optimize your Kubernetes cybersecurity, implement a least privilege-based access management system. Structure your permission levels according to the bare minimum access necessary for users to do their work, and disallow access to anything more.

3. Use Multi-Factor Authentication (MFA)
Multi-factor authentication adds an extra layer of cybersecurity to your K8S platform. A simple password is no longer enough in today's threat landscape, and MFA requires users to provide additional information to log in to your system. Some common types of MFA are:

• SMS/email
• Authenticators
• Biometrics (fingerprints, retinal scans, voice patterns, user behavior)
• Digital Certificates
• Security Tokens

Research from Google has shown that MFA can reduce the likelihood of a breach by over 99% in some cases. The exact numbers may vary based on the configuration of your K8S environment, but one thing is clear: Integrating MFA into your Kubernetes system can significantly reduce the likelihood of a breach. If you want to strengthen your K8S system, you'll want to implement MFA.

4. Regularly Update and Patch Clusters
Attackers often attempt to exploit long-standing vulnerabilities, especially those that could have been resolved with an update or patch. Stale Kubernetes containers may still possess these vulnerabilities, leaving your network exposed.

Updating your clusters and frequently applying patches are essential ways of remediating vulnerabilities. The exact frequency may vary with your application, but make routine patches and updates a part of your K8S security best practices.

5. Implement Pod Security Standards
Kubernetes' Pod Security Standards put forth three broad policies to outline where an organization's needs lie on the security spectrum. They are:

- Privileged: Provides the broadest possible level of permissions.
- Baseline: Allows the default (minimally specified) pod configuration.
- Restricted: The most heavily controlled policy, it follows current pod hardening best practices.

By applying Pod Security Standards to your K8S environment, you can lay a foundation for how to restrict pod behavior. This minimizes the risk of a breach or unauthorized lateral movement and enhances security across each pod and cluster in your environment. As you implement your Kubernetes security best practices, consider using the Pod Security Standards to lay out a broad framework for your operations.

6. Implement Role-Based Access Control (RBAC)
Role-Based Access Control (RBAC) is a highly granular access control method that restricts your users from certain assets based on their position within your organization. It grants users access only to the most essential resources they need to perform their tasks and reduces the likelihood of an unauthorized user gaining access to a Kubernetes node or cluster and then moving laterally to breach other assets.

RBAC should be prioritized as a Kubernetes security best practice. The process can take some know-how, so consider using a third-party solution with the expertise that can simplify the process.

7. Use Network Policies to Control Traffic
Network policies restrict which entities your pod is allowed to communicate with. Kubernetes bases its network policies on three identifiers, which serve as criteria for assessing whether you can share information between pods. They are:

• Other allowable pods
• Allowable namespaces
• IP blocks

With these policies, your team can monitor your network traffic and discern between active and permissible traffic, which helps you identify network anomalies and areas of unnecessarily granted permission. Security teams should implement network policies to regulate how your pods communicate and who they can communicate with so you can keep your network secure.