Top 8 Kubernetes Application Security Best Practices

Introduction

In the current threat landscape, businesses must take a proactive approach to Kubernetes security. As distributed cluster deployments come with an increased number of attack vectors, it’s now crucial to follow Kubernetes application security best practices.

Even if you’re using a managed service, security is ultimately your responsibility. As such, it’s important to address key platform dependencies and architectural vulnerabilities by enforcing Kubernetes best practices.

According to a recent study, 59% of respondents stated that they detected misconfigurations over the past year, resulting in application deployment delays. This makes it vital to implement security best practices right from the beginning to avoid potential delays and related expenses.

Shifting Security Left and Enforce Policy-as-Code

Kubernetes helps DevOps teams innovate securely at lightning speed, provided that they enforce robust governance policies. This approach helps deploy governance-as-code throughout the whole Kubernetes infrastructure.

When you shift security left and apply policy-as-code programmatically, your organization will benefit from a “robot guard” who is always alert, 24/7, all year round. To make this happen, both deployment and security teams must work closely together to define, deploy, and manage Kubernetes governance policies. In this scenario, you can leverage a policy enforcement platform or use an open policy agent.

Shifting left also allows DevOps teams to unleash automated operators (like a robot guard) within your Kubernetes cluster or cloud infrastructure. These automated operators will monitor your repositories for changes in real-time and trigger an automatic update once a change is detected.

However, before shifting left, make sure to develop a centralized playbook to enact and enforce security protocols across the application development cycle. Whenever you enforce policy-as-code by shifting left, you can seamlessly normalize hybrid environments and attain exceptional levels of governance across all clusters from a single source of truth.

Enable Role-Based Access Control (RBAC)

By design, Role-Based Access Control or RBAC restricts user access to valuable resources based on user role and related permissions. This type of privileged user access allows development teams to award different levels of access to assets. How much access a user has depends on the rules set in Roles or ClusterRoles.

If you don’t set a specific role within the constraints of a namespace, it will remain in its “default” setting. So, it’s important to use API namespaces and resources to ensure secure access.

For example, to configure NetworkPolicy resources, you can use Magalix Rego templates to scan and validate that the resource is enforcing the right network security rules leveraging Magalix policy-as-code. But as ClusterRoles aren’t bound by any specific namespace, you can enable API access by granting granular permissions to specific users.

Consistently following the least privileged principle and closing all entry points by default, makes securing your environment much easier.

Enforce Zero-Trust Policies

After implementing RABC, DevOps teams and security personnel can add another security layer by enforcing zero-trust policies. Zero-trust takes RABC to the next level by ensuring that anyone accessing corporate networks continuously proves that they have all the necessary rights and permissions to access resources.

We all know that a simple username and password just doesn’t cut it anymore. So, it’s always better to enable user access through specific permissions within an effective zero trust architecture. In this case, user behavior deemed suspicious or outside of their purview will trigger an alert automatically.

Zero-trust is based on the following five elements:

1.     Application trust.

2.     Data trust.

3.     Device trust.

4.     User trust.

5.     Transport/session trust.

The primary motive here is to stop addressing security from an identity perspective. By enforcing zero-trust protocols from a controlled access standpoint, we can add more breadth to your overall security strategy.

Enable Vulnerability Scanning

As a rule, engage in regular Kubernetes vulnerability scanning to identify and resolve security gaps in your container deployments. It’s critical to scan container images, scan your application’s third-party libraries, and open-source elements within them (and resolve potential vulnerabilities).

You can make this process seamless by automating Kubernetes vulnerability scanning across the Continuous Integration/Continuous Delivery (CI/CD) pipeline. This approach will help ensure that your Kubernetes application meets current compliance requirements and meets established best practices.

Ensure That Secrets Remain Secrets

Always secure sensitive information like passwords, tokens, and SSH keys by leveraging Kubernetes Secret. This approach will prevent the exposure of sensitive data during the development cycle.

For example, when a pod starts up, it will usually need access to its secrets. Once you create a service account, a Kubernetes secret with an authorization token is generated automatically. We can then add another layer of security by encrypting this data in etcd (a highly available and reliable key-value store). This approach will block access to your etcd backups even if an attacker obtains read access.

If third-party integrations demand access to your Kubernetes Secrets, it’s critical to carefully review the requested access and your RABC permissions. It’s important as you can quickly compromise the security profile of your cluster.

Adopt and Enforce OWASP Best Practices

To ensure consistent container security, adopt and enforce Open Web Application Security Project (OWASP). This approach will help developers stay up to date on a broad consensus for critical application security risks. When you enforce OWASP, you can automatically find known vulnerabilities in your web apps. You can also do this in real-time while developing and testing your application.

Monitor Network Traffic in Real-Time and Limit Communications

Most often, containerized applications use cluster networks extensively. This makes it crucial to observe network traffic allowed by your Kubernetes network policy. This approach will help you understand how exactly your application interacts and recognize anomalous communications.

Monitoring will also help you compare both allowed and active traffic to determine which network policies go unused by cluster workloads. You can then use this information to remove unused connections (to reduce the attack surface) and further strengthen your allowed network.

Adopt or Enforce Kubernetes Security Best Practices 

It's also best to embrace or enforce Center for Internet Security (CIS) Benchmark policies, a set of cybersecurity best practices, and a standard at Magalix. This approach helps ascertain your cluster's security against the CIS Benchmark.

If you're using the Magalix Policy Enforcement Platform, you can also enforce Payment Card Industry Data Security Standard (PCI DSS) compliance policies in tandem. PCI DSS is a set of security and compliance standards that help secure credit card transactions while ensuring compliance (of technical operations).

At the same time, you should also include MITRE ATT&CK policies, a framework, and a comprehensive knowledge base of tactics and techniques used by threat actors. When you enforce all these policies together programmatically, you can fortify your applications and overall infrastructure.

At Magalix, we help DevOps teams programmatically enforce security standards with policy-as-code. This approach helps enable developer-centric experiences across CI/CD pipelines and applies governance standards across all clusters with a single click.

This approach also helps validate infrastructure compliance much earlier in the software development lifecycle. As such, DevOps teams can continue to innovate rapidly without compromising security.