Top 8 Open Source Kubernetes Security Tools and Scanners

Kubernetes has quickly become the go-to platform for container orchestration, thanks to its flexibility and scalability and the powerful and engaged community behind it. However, as organizations embrace Kubernetes to run critical applications, it becomes a more lucrative target for malicious actors, and robust security has become a central part of running K8s at scale. 

Fortunately, like many other domains, the open-source community has stepped up to provide a range of tools aimed at securing applications in Kubernetes environments.  As big open source proponents, we love to periodically dive into the ones you should be keeping track of (like this popular post on the 5 OSS Tools All Devs Should Know About).  

In this post we’ll share  eight essential open-source tools and scanners that can help protect your Kubernetes clusters and ensure compliance with security standards.

Key Security Considerations for Running Apps on Kubernetes

Before we dive into the tools themselves, let’s take a look at the most common security concerns when running platforms like Kubernetes.  When deploying applications on Kubernetes, it’s important to keep the following security aspects in mind:

• Configuration Management: Ensuring proper configuration of Kubernetes resources to avoid vulnerabilities.

• Access Control: Managing user permissions and RBAC (Role-Based Access Control) to limit unauthorized access.

• Network Security: Implementing network policies to control traffic between pods and protect against unauthorized access.

• Runtime Security: Monitoring and alerting on suspicious activity within the cluster.

• Vulnerability Management: Regular scanning for vulnerabilities in container images, Kubernetes resources, and third-party components.

• Policy Enforcement: Establishing and enforcing security policies to ensure compliance across the cluster.

Luckily there are fantastic open source tools that help cover these many aspects of maintaining a robust and secure Kubernetes operation.



1. Kube-bench

Kube-bench is a tool designed to evaluate Kubernetes clusters against established security benchmarks, particularly those recommended by the Center for Internet Security (CIS).

Its purpose is to identify configurations that fall short of security best practices, helping teams maintain robust and compliant clusters. 

Kube-bench Key Feature

Kube-bench automates the scanning process, providing a comprehensive report on various aspects of the cluster's security posture. It offers detailed insights into compliance with the CIS benchmark.

These automated checks, based upon security best practices and CIS benchmarks, give you insights into the cluster's security posture and areas needing improvement.

Kube-bench Use Case

After deploying a Kubernetes cluster, an organization wants to ensure compliance with industry security standards. They use Kube-bench to automatically assess their cluster against the CIS Kubernetes benchmark.

This process identifies any configuration issues that may expose the cluster to vulnerabilities, such as improper RBAC settings or weak network policies. Based on Kube-bench’s findings, the team can quickly prioritize and address security gaps to align with best practices.

2. Kube-hunter

Kube-hunter is a penetration testing tool for Kubernetes, aiming to uncover vulnerabilities within clusters by simulating an attacker’s perspective. This tool helps administrators gain visibility into potential risks, providing a proactive approach to cluster security.

By focusing on real-world attack vectors, Kube-hunter offers a practical assessment of the cluster’s defenses and helps teams prioritize security improvements.

Kube-hunter Key Features

Its primary strength is performing active reconnaissance to discover misconfigurations, exposed services, and common weak points in Kubernetes setups.

It identifies common security weaknesses such as exposed dashboards, unsecured kubelets, and accessible ports.  This tool is ideal for gaining an overview of potential risks before they become significant threats. 

Kube-hunter Use Cases

A company conducting a security audit on its Kubernetes environment deploys Kube-hunter to simulate an attack. Kube-hunter identifies potential vulnerabilities, such as an exposed Kubernetes dashboard or misconfigured API server.

This simulation allows the security team to proactively harden the cluster by addressing misconfigurations and implementing additional network policies to minimize the attack surface.

3. Kubescape

Kubescape is an end-to-end Kubernetes security platform that assesses clusters based on multiple security frameworks, such as NSA guidelines and MITRE ATT&CK. Its goal is to provide a holistic view of cluster security, identifying potential risks and misconfigurations across different layers.  

Kubescape Key Features

With capabilities for posture management, risk assessment, and compliance scanning, Kubescape ensures that clusters adhere to both organizational and industry standards. Its multi-layered approach allows it to detect security gaps at various levels, from configuration settings to workload-specific risks.

It practically offers posture and risk assessment, as well as misconfiguration detection, helping ensure robust security across different facets of your Kubernetes environment.

Kubescape Use Cases

As part of a compliance initiative, a healthcare provider uses Kubescape to assess its Kubernetes clusters against NSA guidelines. Kubescape highlights potential risks associated with sensitive data handling and points out areas that need improvement, such as pod security policies and network segmentation.

The tool's multi-layer scanning capabilities enable the provider to meet regulatory requirements while enhancing overall security posture.

4. Trivy

Trivy is a versatile tool that specializes in scanning container images and Kubernetes resources for vulnerabilities, misconfigurations, and hidden secrets. It helps development teams secure their environments from the outset by integrating seamlessly into CI/CD pipelines. 

Trivy Key Feature

Trivy’s scanning capabilities extend across multiple layers, from OS-level vulnerabilities to application-specific issues. It provides a fast, efficient scan process and supports integration with various container registries and Kubernetes setups, making it an ideal choice for teams aiming to catch vulnerabilities early in the development cycle.

It scans for operating system vulnerabilities, misconfigurations, and secrets within Kubernetes resources and container images, making it a comprehensive solution for securing your entire stack.

Trivy Use Cases

A development team integrates Trivy into their CI/CD pipeline to automatically scan container images for vulnerabilities before deployment.

Trivy flags outdated packages in a base image that contain known vulnerabilities, allowing the team to update these packages and rebuild the image. By scanning images during development, the team ensures that only secure images make it to production, reducing the risk of deploying vulnerable software.

5. Falco

Falco is a runtime security tool for Kubernetes that offers real-time monitoring and detection of suspicious activities. Its focus is on observing system calls to identify abnormal behaviors, providing teams with timely alerts about potential threats.

Falco’s strength lies in its customizable rules engine, which allows teams to define specific behaviors that should trigger alerts. 

Falco Key Features

By applying rules to system call activity, Falco can alert on abnormal behavior that may indicate security threats, such as privilege escalations or unauthorized file access, and other indicators of compromise, enabling quick responses to threats as they unfold.

Falco Use Cases

During an incident response exercise, Falco detects a suspicious system call indicating potential privilege escalation in a Kubernetes pod.

The security team receives an alert and is able to isolate the affected pod immediately. Using Falco, the team monitors real-time events to detect and respond to unusual behaviors, such as unauthorized file access, in a timely manner, which helps minimize the impact of potential attacks.

6. Prowler

Originally an AWS-focused tool, Prowler has expanded to include checks for Kubernetes clusters, making it a valuable resource for teams seeking to enforce security best practices across both cloud and container environments.

Prowler provides a flexible, modular approach to security assessments, with checks that cover network configuration, access control, and compliance with organizational policies.

Prowler Key Feature

By providing comprehensive security assessments for Kubernetes, cloud and Kubernetes teams are able to stay informed about their security posture. This helps teams maintain consistent security standards across Kubernetes clusters and other cloud resources.

Prowler Use Cases

A financial services company with a cloud-native infrastructure uses Prowler to scan its Kubernetes clusters as part of a broader cloud security assessment.

While the tool is well-known for AWS security, Prowler’s Kubernetes-specific checks help the team assess configurations, ensuring that sensitive financial data remains protected and compliant with security standards.

7. Syft + Grype

Syft is a tool for generating Software Bill of Materials (SBOMs), while Grype is a vulnerability scanner that works with SBOMs to detect security issues. They are complementary vulnerability scanners that together offer a comprehensive solution for identifying vulnerabilities in container images, with a focus on software supply chain security. 

Syft + Grype Key Feature

Syft’s SBOM generation helps maintain an inventory of software components, while Grype scans these components for known vulnerabilities. This combination provides an in-depth view of container security, allowing teams to address potential risks before they reach production. This duo is a powerful combination for Kubernetes environments, allowing you to scan container images for vulnerabilities and ensure compliance with security standards.

Syft + Grype Use Case

A software company that ships containerized applications generates a Software Bill of Materials (SBOM) using Syft to maintain an inventory of all components within their images. They then use Grype to scan the SBOM for vulnerabilities, ensuring that no known vulnerabilities are being deployed with the application. This approach allows the company to maintain security and compliance standards in their supply chain while reducing the likelihood of unintentional vulnerabilities.

8. OPA (Open Policy Agent) with Gatekeeper

OPA is a policy enforcement framework for Kubernetes, while Gatekeeper is an admission controller that enforces these policies.

OPA is a general-purpose policy engine, and when paired with Gatekeeper, it becomes a powerful tool for enforcing security policies within Kubernetes. Together these enable organizations to define and enforce policies as code, ensuring consistent governance across clusters. 

OPA Key Feature

OPA with Gatekeeper allows for dynamic policy enforcement during admission control, blocking non-compliant resources from being deployed.

They support extensive customization, enabling teams to tailor policies to specific organizational needs, thereby strengthening security and compliance in Kubernetes environments.

Ensuring compliance with security policies by validating Kubernetes resources during admission control, allows organizations to enforce security standards consistently across your clusters.

OPA Use Case

A telecommunications company wants to enforce strict security policies in its Kubernetes clusters, such as disallowing deployments with privileged containers.

By implementing OPA with Gatekeeper, they establish these policies as code, ensuring every deployment adheres to predefined security standards. Any policy violations are flagged during admission control, preventing non-compliant configurations from being deployed in the cluster.

Why Check out these Kubernetes Security Tools?

Each of these tools plays a distinct role in securing Kubernetes environments, from initial vulnerability assessments to real-time threat detection and policy enforcement. By incorporating these tools into your security strategy, you can effectively safeguard your Kubernetes clusters and enhance their resilience against potential threats.

Securing a Kubernetes cluster requires a multi-faceted approach, combining vulnerability management, policy enforcement, and runtime security.

Tools like Jit simplify the process of adopting these tools by integrating them into a single and unified platform so you can derive the benefits of leveraging tools like Prowler, Kubesec, Trivy, and Syft + Grype without having to integrate, configure and maintain them yourself––enabling engineering teams to streamline and automate security tasks.

Adopting these open-source tools can help safeguard your Kubernetes environments end-to-end, giving you the peace of mind you need to scale and operate your applications on Kubernetes.