Kubernetes Security – The Latest Update

In the rapidly evolving digital environment, companies are turning to containerization to deploy and expand their applications efficiently. With numerous container orchestration platforms to choose from, Kubernetes has become the dominant standard, offering a resilient and adaptable structure for managing containerized workloads. Nevertheless, as the utilization of Kubernetes increases, so does the importance of implementing robust security protocols to safeguard the valuable resources and sensitive information stored within the Kubernetes system.

Evidence of this is the recent Red Hat’s 2023 report on Kubernetes security which discloses alarming statistics. According to the report, a 7% rise in respondents considered security investment in containerized operations inadequate. Meanwhile, 67% have to slow down cloud-native adoption due to security concerns, emphasizing the urgency for organizations to address these issues and safeguard their software supply chain.

This shows that more than simply checking off boxes or installing security tools is needed to ensure the security of Kubernetes. It’s necessary to have a deep understanding of the platform’s architecture, potential vulnerabilities, and effective risk mitigation practices. In light of this, this blog post aims to thoroughly examine Kubernetes security, covering recent security updates, providing helpful implementation tips, and exploring how users commonly address security threats and minimize potential risks.

Kubernetes Security Overview

Kubernetes Security is a critical aspect of maintaining a secure container orchestration platform. It encompasses various layers of security across the 4C’s of cloud-native security: Cloud, Cluster, Container, and Code. Here is detailed information about each of these aspects.

  • Cloud Security

The underlying physical infrastructure, whether a corporate data center, collocation facility, or cloud provider, forms the foundation of Kubernetes security. It is essential to follow best practices for cloud providers or physical security to ensure the overall safety of the Kubernetes cluster.

  • Cluster Security

Securing a Kubernetes cluster involves multiple considerations. Firstly, safeguarding the Kubernetes API is the primary entry point for managing the cluster. Implementing authentication, authorization, and encryption mechanisms for the API server is crucial to prevent unauthorized access and data breaches.

Secondly, securing the applications within the cluster is essential. As cloud-native applications are typically designed around micro-services and APIs, the security of the entire application relies on the safety of individual services. Ensuring that each application component follows secure coding practices, implementing access controls, and performing regular vulnerability assessments are vital to mitigate security risks.

  • Container Security

Containers play a significant role in Kubernetes, and their security is paramount. Employing secure container images, regularly patching and updating container runtime, and implementing container isolation mechanisms (such as Kubernetes namespaces and security contexts) are crucial to prevent container-level attacks and maintaining the workload’s integrity.

  • Code Security

The code running within Kubernetes pods should undergo thorough security reviews and testing. Secure coding practices should be followed, including input validation, proper error handling, and protection against common vulnerabilities (such as injection attacks and cross-site scripting). Implementing container image scanning tools and code analysis tools can help identify and mitigate security issues early in the development life-cycle.

Key Components for Kubernetes Security

Control Plane Components

  • API Server:

The API server is the central communication hub for managing the cluster. Securing the API server involves enabling authentication, implementing role-based access control (RBAC), and leveraging transport layer security (TLS) encryption for secure communication.

  • Scheduler:

The scheduler assigns pods to worker nodes based on resource requirements and constraints. Securing the scheduler involves protecting its configuration and ensuring only authorized entities can make scheduling decisions.

  • Controller Manager:

The manager oversees various control loops, such as managing replication controllers, maintaining desired pod states, and handling node failures. Securing the controller manager involves limiting access to its API and ensuring the integrity of its configuration.

  • Etcd:

Etcd is a distributed key-value store for storing Kubernetes cluster state. Securing Etcd involves enabling authentication, encrypting data in transit, and implementing access controls to protect sensitive cluster information.

  • Cloud Controller Manager:

The manager integrates Kubernetes with the underlying cloud provider’s services. Securing the cloud controller manager involves following the cloud provider’s security best practices and implementing proper authentication and authorization mechanisms.

Worker Node Components

  • Kubelet:

The kubelet runs on each worker node and manages the containers within pods. Securing the kubelet involves configuring strong authentication and authorization for kubelet API requests and regularly updating it to address any security vulnerabilities.

  • Kube-proxy:

Kube-proxy enables network communication between pods and services within the cluster. Securing kube-proxy involves implementing network policies, restricting access to the kube-proxy API, and monitoring network traffic for anomalies.

  • Container Runtime:

The container runtime, such as Docker or container, executes and manages containers on the worker nodes. Securing the container runtime involves regularly updating it with the latest security patches, enabling secure container image verification, and enforcing container isolation through appropriate runtime configurations. Organizations can significantly enhance the overall security posture of their Kubernetes deployments by addressing security considerations at each layer of the Kubernetes stack.

Storware Backup and Recovery for Kubernetes

Kubernetes 1.27: Latest Security Updates

Keeping abreast of the latest security updates is essential to maintain a secure Kubernetes environment. Here are the critical updates on the v1.27 and their impact:

  • Kubelet seccomp by default

With this release, Kubernetes introduces a new feature that enables a default seccomp profile for each workload on a node. By streamlining the application of seccomp filters across the cluster, this update simplifies the process of mitigating container breakout attacks and enhances overall security.

  • User namespaces

Kubernetes 1.27 includes improved support for user namespaces, an essential Linux feature that allows processes to operate as root users without compromising the underlying host. This alpha release paves the way for enhanced privilege management and heightened security for applications running as root.

  • Accessing node logs via kubectl

A new alpha feature enables cluster operators to conveniently access system logs on cluster nodes through the Kubernetes API. This update enhances cluster security by reducing the need for manual SSH connections while providing easier log management on Linux and Windows systems.

  • Self user attributes

Kubernetes 1.27 introduces an API endpoint that grants users clear visibility into their identities within the cluster. Troubleshooting access issues and determining role-based access control (RBAC) rules become more streamlined, empowering users to identify themselves and navigate the cluster more effectively.

  • Kubernetes CVE Feed

Keeping track of vulnerabilities is now easier with the updated CVE feed in Kubernetes 1.27. The feed is fully compatible with the JSON specification, allowing seamless integration with various tools for parsing and managing vulnerability information.

Common Security Threats to Kubernetes

It is essential to comprehend the common security threats to Kubernetes to mitigate them effectively. Here are some significant dangers and their consequences:

  • Container Breakouts

Hackers can access the host operating system from within a container, resulting in unauthorized access, privilege escalation, or further compromise of the host environment.

  • Pod-to-Pod Network Attacks

Insecure network policies or misconfigured network controls can allow attackers to move laterally between pods, potentially compromising sensitive data or unauthorized execution of actions.

  • Insecure Images and Vulnerabilities

Using outdated or vulnerable container images can expose applications to known exploits. Attackers may exploit these vulnerabilities to gain unauthorized access or execute malicious code within Kubernetes clusters.

To mitigate these threats, the following measures should be implemented:

  • Restrict privileges and prevent unauthorized access by implementing RBAC (Role-Based Access Control).
  • Control pod-to-pod communication by applying policies that allow only necessary connections.
  • Keep container images updated with regular updates and patches to address known vulnerabilities.
  • Identify and remediate vulnerabilities in container images by utilizing scanning tools.
  • Enforce security policies and restrict container capabilities using seccomp profiles and AppArmor.
  • Protect data integrity and confidentiality during transit by implementing network segmentation and encrypted communication (TLS).

Securing Containerized Workloads in Kubernetes: Insights from the State of Kubernetes Security 2023

As published by Red Hat Inc., the State of Kubernetes Security for 2023 report sheds light on the evolving security landscape of containerized workloads in Kubernetes. Based on a survey of 600 professionals, it identifies common security challenges, best practices, and their impact on businesses. Here are key takeaways from the report:

  • Investment Gap

Despite the growing adoption of Kubernetes, 38% of respondents feel that security investment in containerized operations needs to be improved. Organizations must prioritize cloud-native security solutions and integrate security tools throughout the CI/CD pipeline and infrastructure to bridge this gap effectively.

  • Security Concerns

Security concerns can impede cloud-native adoption, with 67% of respondents experiencing delays in application deployment due to security concerns.

Security incidents can have severe business impacts, including employee termination, fines, revenue loss, customer dissatisfaction, and damage to reputation.

  • Software Supply Chain Security

Software supply chain security is a pressing concern, with vulnerable application components and insufficient access controls being top concerns. Over half of the respondents have encountered issues related to vulnerable components and weaknesses in the CI/CD pipeline. Organizations should prioritize security early in their cloud-native strategy to mitigate these risks.

By investing in cloud-native tools with built-in security, adopting a comprehensive DevSecOps approach, and focusing on software component security and automation, businesses can protect their assets, meet regulatory requirements, maintain customer trust, and reduce the cost of remediating security issues.

Final Thought

Enhancing Kubernetes security is vital for managing containerized applications. To bolster your security posture, understand common risks, follow best practices, and stay updated on the latest updates. Also, staying vigilant, informed, and adaptable to new threats would be best. By taking a proactive and comprehensive approach to Kubernetes security, safeguard your applications, data, and infrastructure effectively.

Remember, security is an ongoing effort, so prioritize and evolve your security measures to avoid potential vulnerabilities.

text written by:

Grzegorz Pytel, Presales Engineer at Storware