Container security means keeping your containerized apps secure. Kubernetes security is critical; in recent years it has been adopted by 61% of organizations, and one of RedHat’s surveys reveals that 67% of the people surveyed have put off or slowed down rolling out container-based applications because they’re worried about security.

This post will cover the challenges, best practices, and tools to maintain a safe container environment. From building pipelines to runtimes, we’ll give you practical advice for your container security strategy. We’ll also dive into Kubernetes security best practices to secure every deployment stage. 

Summary

• Container security means security across the entire software development lifecycle, including pipelines, container images, host machines, runtimes, and orchestration platforms.

• Key parts of container security are image scanning, runtime protection, network security, logging and monitoring, and vulnerability management with tools like Aqua Security, Falco, Calico, and Kubernetes Network Policy. The host operating system security and configuration are critical to prevent attacks and ensure a container’s smooth operation.

• Best practices for containers include using trusted images, RBAC, least privilege, and integrating security into CI/CD pipelines for continuous monitoring and rapid incident response.

What is Container Security?

Container security means applying security tools and policies to your containerized apps to protect them from threats and putting in place solid defenses against security vulnerabilities.

Containers deploy apps as isolated, self-contained packages, they share the OS kernel, and they are faster and lighter than VMs. But this also introduces new security challenges as containers hide visibility and have a larger attack surface.

Regarding Kubernetes security, its official website states that “Kubernetes includes several APIs and security controls, as well as ways to define policies that can form part of how you manage information security.”

Container security must be embedded in all the processes and resources containers depend on for it to be effective. It’s part of the overall container environment security. This must be done across the entire software development lifecycle:

• Build pipelines

• Container images

• Host machines

• Runtimes

• Orchestration platforms

Also, securing the operating systems that host container environments is key. Installing the latest versions and hardening these operating systems is critical to managing vulnerabilities and attack vectors for Kubernetes clusters.

By doing container security at every stage you can secure your containerized apps.

As containers move into production, the security of mission-critical containers is part of an organization’s overall security strategy.

Container Security Components

Container security needs a multi-layered approach that includes isolation, container image security, runtime security, network security, logging, monitoring, and vulnerability management. Don’t run containers as a root user to improve security and prevent attacks that exploit elevated privileges.

Key features of container security solutions are image scanning, runtime protection, network security, and compliance.

Each of these is part of a containerized environment.

Image Scanning

You should scan your container images regularly to not deploy compromised containers. Continuous scanning helps to not include libraries with known issues and detect new vulnerabilities that emerge daily. Keeping your container images up-to-date means using the latest components and patching vulnerabilities to reduce the attack surface.

Here are a few container scanning tools:

• Aqua Security

• Anchore

• Clair

• Prisma Cloud

These scan containers for security vulnerabilities. They do deep-layer vulnerability scanning of container images in registries and CI/CD pipelines, detecting known vulnerabilities, misconfigurations, and malware.

Open-source vulnerability scanners like Trivy or Grype can also be used for container image scanning.

Container Runtime Security

Container runtime security is critical to protect containers from threats and vulnerabilities while they are running in the runtime environment. This means monitoring container runtimes for process executions and network flows, detecting abnormal activity, and remediate threats in real time.

Runtime detection and response is an additional layer of protection against threats targeting running pods.

You must monitor for suspicious activity to prevent attackers from gaining access to your Kubernetes clusters, which can lead to serious security breaches such as data exfiltration and disruption of critical services.

Tools like Falco can be used to improve runtime security by monitoring activities in container environments. These tools help to establish behavioral baselines for anomaly detection and block malicious processes and files.

Network Security

Network security is important in container environments because containers need to talk to each other and external services. Ensuring those communications are secure is key to data integrity and confidentiality. Network policies in Kubernetes mean setting rules for inbound and outbound traffic, to restrict access to only essential services. This helps to secure and manage the network traffic within the system.

Network segmentation controls and secures container-to-container and container-to-external communications, so if an attacker gets into one container the damage is limited.

This segmentation is key to preventing attackers from moving laterally across containers in the Kubernetes cluster. Using firewalls and encryption on top of segmentation further reduces the risk of network attacks on containers.

Container network security can be done using:

• Calico

• Flannel

• CNI plugins like Istio and Cilium

• Kubernetes Network Policy

• Prisma Cloud

These provide additional security for containerized environments. Monitoring network traffic helps to understand how applications talk to each other and identify unexpected communication patterns, which tightens network policies and reduces attack surface.

Traditional network security methods don’t work in container environments because of the dynamic nature of container IP addresses, so identity-based models should be used.

Securing Containers

Securing containers requires a holistic approach that covers many points in the software supply chain. This section will cover best practices for securing containers, including using trusted images, RBAC, and least privilege.

Use Trusted Images

Container images should only come from trusted sources. Here are the steps:

1. Choose base container images from trusted registries.

2. Make sure container images are up to date.

3. Scan container images for vulnerabilities.

By doing this you have secure container images.

Updating and patching container images reduces the attack surface by removing unnecessary packages and dependencies.

RBAC

Role-Based Access Control (RBAC) ensures that only authorized people can deploy and manage containers by assigning roles and permissions. Kubernetes uses RBAC to manage permissions, so users only have access to what they need based on their roles. To enable RBAC start the Kubernetes API server with the –authorization-mode flag set.

RBAC in Kubernetes matches users or groups to a set of permissions linked to roles based on verbs and resources. This helps in controlling access to resources, reducing the risk of unauthorized access and overall security.

Least Privilege

The principle of least privilege is to minimize the privileges given to containers and users to reduce the risk of privilege escalation. Containers should run as non-root users to reduce the risk of privilege escalation. Don’t run containers as root in privileged mode to minimize their access to the host system.

By having containers run with only what they need the attack surface is reduced, and container security is improved.

Kubernetes Best Practices

Securing the container orchestration platforms that deploy, scale, and run containerized applications is key. This section will cover protecting the Kubernetes API server, securing etcd, and pod security policies.

Protecting the Kubernetes API Server

The Kubernetes API server must be protected to secure the entire cluster. Audit logs can help to track all activities in chronological order for compliance and forensic analysis in case of security incidents.

Securing etcd

etcd stores all sensitive data including:

• Secrets

• Service data

• Pods

• Other critical states

Strong access controls and encryption mechanisms like TLS and external key management systems should be used to protect etcd data.

Firewalls around etcd nodes can control network traffic, only allow necessary and secure traffic to and from etcd. Use strong, unique credentials for etcd access to reduce the risk of unauthorized access.

Pod Security Policies

Pod security policies are key to securing containers by enforcing security standards and preventing bad configurations. Limiting resource permissions ensures containers only have access to what they need and therefore the applications and data they contain.

Monitoring and Incident Response

To secure containerized environments, monitoring and incident response is key. Continuous monitoring is real-time observation and analysis of container activities throughout their lifecycle, allowing for early detection and response to threats.

Continuous Scanning

Continuous scanning adapts to the dynamic nature of container environments, providing ongoing risk assessment. To fix vulnerabilities, update the source image and then redeploy the containers. Don’t update the running containers.

Anomaly Detection

Anomaly detection in container behavior means:

• Monitoring and analyzing deviation from normal usage patterns

• Ensuring containerized applications’ replicas are nearly identical

• Investigate if a replica deviates significantly from the others.

System call interception and analysis are techniques to detect unusual behavior in running containers. Process whitelisting can help to detect unexpected processes in a Kubernetes environment.

Incident Response Plan

An incident response plan for containerized environments is key to securing and containing threats quickly. The plan should include automated actions like isolating compromised containers to prevent the spread of threats.

Use Security Information and Event Management (SIEM) tools to detect threats, investigate events, and reduce response time. Take a structured approach to quickly identify and remediate CI/CD security threats, and reduce response time and overall security posture.

Security in CI/CD Pipelines

Security in CI/CD pipelines is key to making sure that security is embedded in every stage of the software supply chain. Shifting security left means testing and fixing issues early in the development lifecycle.

Automated Testing

Security assessment in the build process is key to vetting all code for production and scanning for security vulnerabilities before deployment. Use automated security tests throughout CI/CD workflows to detect vulnerabilities and secure pull requests.

Run application security tests to ensure source code is vulnerability-free and notify teams of pipeline vulnerabilities. Combine automated tests with remediation tools to protect against attack vectors in CI/CD pipelines.

Configuration Management

Configuration management is key to consistent and secure deployments. Infrastructure-as-Code (IaC) helps to manage and provision cloud infrastructure through code, reducing errors.

Use GitOps and Infrastructure as Code (IaC) to simplify and automate Kubernetes. Use KubeLinter to detect misconfigurations and security issues in Kubernetes configurations, only allow authorized users to access.

Follow GitOps patterns to ensure configurations in the CI/CD process match the desired state, reducing human error.

More Security

More security layers for containerized environments are always welcome, including container sandboxing, kernel module loading, and centralized policy management.

Container Sandboxing

Container sandboxing adds security by isolating running containers from the host OS and other OSes in the security context, preventing breakout attacks.

Unlike runC, Sandboxed-Container prevents security risks by isolating applications in virtual machines with dedicated guest OS kernels, reducing the attack surface.

Preventing Kernel Module Loading

Disabling certain kernel modules can prevent unauthorized access and security exploits. Using a Linux security module like SELinux or AppArmor can block unwanted kernel module loading, and secure the container runtime environment.

Centralized Policy Management

Centralized policy management ensures security policies are enforced consistently across containerized environments. Tools like Open Policy Agent (OPA) help enforce consistent security policies and provide a flexible and scalable way to manage policies.

OPA supports many use cases and integrations, making it easier to update policies and run audits.

Using OPA or similar tools like Kyverno or Validating Admission Policy ensures security policies are applied consistently across all container deployments, overall security, and compliance.

FAQ

What is container security?

Container security is about securing containerized applications by using security tools and policies to mitigate risks.

Why is image scanning important in container security?

Image scanning is important in container security because it prevents compromised containers from being deployed and ensures images are up-to-date and secure.

How does RBAC help in container security?

RBAC helps in container security by assigning roles and permissions to authorized users, reducing unauthorized access. This is key to securing container environments.

What are more security features for containers?

To secure containers use container sandboxing, prevent kernel module loading, and use centralized policy management tools like Open Policy Agent (OPA). These will help you with container security.

Why is continuous monitoring important for container security?

Continuous monitoring is important for container security because it allows real-time observation and analysis of container activities, detects threats early and responds, and keeps dynamic container environments secure.

Conclusion

In summary, securing containerized environments is a layered approach. From understanding the basics of container security to advanced security features, each step is key to your applications and data.

Follow best practices, security in CI/CD pipelines, and continuous monitoring and incident response to reduce your container security posture. Use these to make your container deployments threat-resilient.