You must understand what Kerberos is and how it works by reading the previous article. It gives a proper overview of what Kerberos is and how to exploit it.
What is Kubernetes?
Kubernetes is a portable, adaptable, open-source system for managing containerized workloads and services that enables declarative setup and automation.
Kubernetes’ meaning comes from the Greek word for “helmsman” or “captain.” K8s are derived from having to count the eight letters between the letter “K” and “s.”
It boasts a diverse and rapidly developing ecosystem. Kubernetes services, support, and tools are widely available.
What is Kubernetes Security?
Security is a significant consideration in how organizations adopt cloud-native technology, and it is often far more challenging to manage than simply spinning up and running containers.
Kubernetes Security is built around the four C’s of cloud-native stability: cloud, cluster, container, and code.
Cloud: The physical infrastructure that supports Kubernetes is the foundation of its security. Best practices must be followed, whether the cluster is established in one’s own data center or by a cloud provider.
Cluster: Protecting a Kubernetes cluster entails customizable components such as the Kubernetes API and the security of all the cluster’s apps. Because the majority of cloud-native applications are built around microservices and APIs.
Container: Begin with the most miniature code base feasible, avoid assigning extra capabilities to container users, and ensure that containers are inspected for vulnerabilities at compile time.
Code: For any Kubernetes context, code exposes a significant attack surface. Simple policies are examples of simple rules, such as encrypting TCP with TLS handshakes, not exposing unused ports, scanning, and testing. Regular testing can aid in the prevention of security issues in a production environment.
Understanding Kubernetes
Kubernetes is a highly adaptable system for managing very low-level resources generally. It can be deployed on many operating systems on hardware or virtual machine solutions on-premises or in the cloud. It manipulates critical resources.
Defense in depth is a critical security feature that requires the system to protect itself at each level to mitigate attacks that penetrate other layers and limit the scope and damage of the breach. Recognizing the challenge in each layer is the first step in defense in depth.
Containers that conform to one of Kubernetes runtime engines are used. It is completely unaware of what these containers are doing. Quotas allow you to place restrictions on containers. You can also restrict their access to the rest of the network.
Malicious pictures are those that contain code or configuration that was created by an attacker to cause harm or collect information.
It can be introduced into your image preparation workflow and your image repositories.
Vulnerable pictures are images built with a vulnerability that allows attackers to gain control of the operating container or cause other harm, such as injecting their code later.
Why is Kubernetes security important?
Because of the dispersed, dynamic nature of a Kubernetes cluster, Kubernetes security is critical throughout the container lifetime. Each of the three phases of an application’s lifecycle requires a different security approach: build, deploy, and runtime. Kubernetes has inherent security benefits.
Furthermore, because individual pods are temporary and ephemeral, the constantly changing runtime environment can provide IT security experts with issues, as applications and API linkages to other apps and services are continually in motion.
The following Kubernetes security tools are being used:
- Reduce the time required to check that the code is free of compromises.
- Provide digital signatures to increase the trustworthiness of the code.
- Visibility and transparency should be provided not only in code but also in configuration issues.
If a Kubernetes deployment is compromised, it can compromise a massive number of nodes running various microservices. As a result, it risks the company and may impair its day-to-day operations.
The CVE demonstrates how an attacker can use an unbound write function to manipulate kernel memory and gain access to any other processes running on that node.
Providing cluster security
We may now focus on cluster security once the security of a container has been guaranteed. Understanding how Kubernetes operates is critical in this case. We send a request, which is processed, saved in the etcd, and then receive a response.
It sounds like a fancy HTTP server with a backend, etcd. Then, to safeguard access to the cluster, we can start with security rules that apply to a simple HTTP server.
It was merely a file with static user: passwords for basic authentication, which is already deprecated in K8S. Client certificates are another option. To enable this, we must supply a CA file to the API server, which will be used to validate user-supplied certificates.
To enable this, we must supply a CA file to the API server, which will be used to validate user-supplied certificates.
The final approaches are webhooks and proxy authentication. We have combined these because they’re simply a delegation of the logic required to validate the user.
In the case of webhooks, the Kubernetes API server merely forwards the token to the logic that must reply in the appropriate format. As a result, the user will be authenticated or not based on that logic.
In proxy authentication, the proxy server is responsible for authenticating the user and inserting additional headers containing user and group information into the request.
Best Practices
Use a minimal host operating system, disable read-only mounts, and experiment with alternative options for even greater control.
Scan files for vulnerabilities from top to bottom, including OS and other images. There isn’t such a thing as a trustworthy third party.
Include security features such as picture scanning in the CI/CD pipeline.
Keep the cluster safe. Configure RBAC to limit API server access and ensure that all etcd communications are TLS encrypted.
Use Kubernetes’ developed controls, such as defining security context to limit module access.
Monitoring process activity, communications within services, and communications outside the cluster should all be part of proactive security.