Container Security Best Practices

8 no-brainer container security best practices + the key components of container architecture to secure

7 min read

Container Security: A refresher

Container security refers to the set of practices, tools, and measures implemented to secure the entire containerized application development and deployment lifecycle.

Container technology has become a cornerstone of modern software development due to its ability to package an application and its dependencies into self-contained and portable units. This level of portability and consistency across environments has made it popular with developers. However, the distinct structure of containers brings about particular security challenges that organizations need to tackle.

Why container security is crucial across the software development lifecycle

Security breaches can occur at any stage of the software development lifecycle (SDLC), from the initial development and build phase to the deployment and runtime stages. This means that companies require integrated security measures that span the entire lifecycle. 

For instance, vulnerabilities can be introduced during the development stage due to insecure container images or misconfigurations. During deployment, insecure orchestration settings or insufficient network controls can expose the application to threats. Finally, at the runtime stage, a lack of visibility and monitoring can make it difficult to detect and respond to security incidents on time.

The more widely companies use containers, the more likely they are to call security their top challenge with containers.

CNCF Annual Survey

Key components of container architecture to secure

Securing a containerized environment involves protecting several critical components of container architecture. These include:

  • Container images: As the building blocks of containers, make sure to scan all images for vulnerabilities and only use trusted and minimal ones.

  • Registries: Control access to container image repositories to avoid unauthorized changes. Use only trusted and verified registries to reduce security risks related to image manipulation. What is a container registry? ->

  • Orchestrators: These manage how containers are deployed and interact; make sure to properly configure their security controls. 

  • Container engine: This is the runtime that runs containers. It must be secured to prevent unauthorized access and ensure containers are isolated from each other and the host system.

The potential impacts of compromise for these components can be summarized as follows:

ComponentsPotential Impact If Compromised
Container Images- Malicious code execution - Compromise of the container's application - Lateral movement within the containerized environment
Registries- Distribution of malicious container images  - Compromise of any containers using the corrupted images
Orchestrators- Breach of all containerized applications - Unauthorized access to data - Disruption of containerized services
Container Engine- Full system compromise - Loss of data - Unauthorized access to all containers

Shared responsibility model in container security

In the realm of cloud computing and containerization, security is often viewed as a shared responsibility between the cloud service provider and the user. 

Under the shared responsibility model, cloud providers generally handle the security "of" the cloud, which includes all the hardware, software, networking, and physical infrastructure they provide. This also extends to container orchestration services they might offer, like Amazon ECS/EKS. Azure AKS, or Google Kubernetes Engine.

On the other side of the model, users take responsibility for security "in" the cloud. This means they deal with protecting the workloads they run on the cloud provider's infrastructure, including their containerized apps. 

In the context of container security, the shared responsibility model emphasizes that while cloud providers offer tools and services to secure the underlying infrastructure and orchestration layer, users must take steps to secure their containers and the applications running within them.

Common challenges in securing containers

Securing containers presents unique challenges that can complicate the task of maintaining a secure environment. Here are some of the most common challenges:

  • Complexity: Containers add a new layer of complexity to the IT environment. They are highly dynamic and ephemeral, often spun up and down in response to demand.

  • Vulnerability management: Containers are often built from images that have many layers, each of which could potentially have vulnerabilities. 

  • Configuration errors: Misconfigurations are a common cause of security incidents in container environments. This can include everything from containers running with excessive privileges to insecure network configurations.

  • Visibility and monitoring: Containers can be challenging to monitor due to their ephemeral nature. Traditional monitoring tools may not be able to keep up with the dynamic nature of container environments, making it harder to detect and respond to security incidents.

  • Supply chain attacks: Containers often rely on a chain of images and components pulled from various sources. If any link in this chain is compromised (e.g., a malicious image in a public registry), it can lead to supply chain attacks.

Addressing these challenges requires combining container-specific security tools, best practices, and a thorough understanding of the container lifecycle and architecture. Organizations also have to remain current on the latest container threats and vulnerabilities.

Ground-level practices to fortify your container security

In the dynamic landscape of container security, it is crucial to implement comprehensive security measures that address threats. These practices should be incorporated into every stage of the software development lifecycle to ensure a robust defense against potential breaches.

  1. Secure Container Images

  2. Reduce the Attack Surface

  3. Leverage Container Security Tools

  4. Prepare an Incident Response Plan

  5. Implement Regular Audits

  6. Enforce Principle of Least Privilege

  7. Update and Patch Regularly

  8. Protect Container Orchestration

Pro tip

Looking to go beyond the basics? Download the Advanced Container Security Best Practices Cheat Sheet for:

  1. – Actionable best practices w/ code examples + diagrams
  2. – A list of the top open-source tools for each best practice
  3. – Environment-specific best practices
Learn more

1. Ensuring Secure Container Images

Secure container images are the foundation of any secure containerized app. Always verify their origin, scan them for vulnerabilities, and use only minimal base images that are safe and trusted. This reduces the risk of introducing vulnerabilities into your environment.

2. Reducing the Attack Surface

Minimizing potential attack vectors is a fundamental security practice. This can be achieved by eliminating unnecessary software, services, and open network ports: The fewer components and services you have, the fewer opportunities for hackers.

3. Utilizing Robust Container Security Tools

Various tools are available to help secure container environments. These include vulnerability scanners to identify potential weaknesses, configuration checkers to ensure best practices are followed, and runtime security monitoring tools to detect and respond to threats in real time.

Pro tip

To be effective, a container security solution must be able to discover and scan containers, hosts, and clusters across cloud-managed and self-managed Kubernetes environments, including serverless containers such as Fargate ECS as well as standalone containers running on VMs.

Learn more

4. Preparing an Incident Response Plan 

Despite best efforts, security incidents can still occur, including those involving container technologies like Docker and Kubernetes. Having a well-defined response plan can help minimize damage and downtime. 

This plan should specifically outline how to identify and recover from a security incident involving containers. It should cover potential scenarios such as container breakout, image vulnerabilities, and misconfigurations. Like any good plan, it should also be regularly updated and tested to ensure its effectiveness and to keep up with evolving threats.

5. Implementing Regular Audits 

Regular audits of container activities, configurations, and components are crucial in maintaining a secure container environment. These audits can help detect any irregularities or deviations from standard operations, which could indicate a potential security issue. This includes auditing container images for vulnerabilities, checking container runtime configurations, and monitoring inter-container communications. 

Audit logs from your container orchestration and runtime platforms should be monitored and analyzed regularly to identify trends and detect anomalies. This aids in maintaining the integrity of your containerized applications and infrastructure.

Pro tip

Kubernetes audit logs and reports mapped to the Center for Internet Security (CIS) Foundation Benchmarks for Kubernetes can help you assess the security of your Kubernetes environments and ensure compliance.

Learn more

6. Enforcing Least Privilege Principle 

Detecting and remediating excessive privileges is critical to securing containers

The principle of least privilege (POLP) dictates that a process should have only the permissions it needs to function and nothing more. In a container environment, this includes limiting container permissions, using read-only file systems where possible, and controlling access to system resources.

7. Updating and Patching Regularly

It's essential for companies to regularly carry out updates and apply patches. This includes not only the container runtime and orchestration tools but also the applications running within the containers and the host systems themselves. Only then can you ensure a continuously secure environment. 

8. Protecting Container Orchestration

Container orchestration systems like Kubernetes and Amazon Elastic Container Service (ECS) can be complex and have their own set of security considerations. 

Protecting Kubernetes will include securing API access, using network policies to control traffic, regularly checking your orchestration configurations, and leveraging built-in security features like role-based access control (RBAC)

For Amazon ECS, some best practices include implementing AWS’ shared responsibility model, zero-trust identity and access management (IAM), and end-to-end encryption. More details on securing ECS can be found in the AWS documentation.

Open-source container security tools by use case

There are various tools that are useful to implement these best practices. The leading open-source tools can be found in the table below:

Use CaseOpen Source Tools
Ensuring secure container imagesClair, Docker Bench
Reducing the attack surfaceCIS Docker Benchmark, Kubernetes Pod Security Policies
Utilizing robust container security toolsFalco, OpenSCAP
Preparing an incident response planTheHive, FIR (Fast Incident Response)
Implementing regular auditsAuditd, GRR
Enforcing the principle of least privilegeKubernetes RBAC, Docker user namespaces
Updating and patching regularlyWatchtower, Anchore Engine
Protecting container orchestrationKubernetes Network Policies, RBAC

By implementing these ground-level practices, you can establish a strong foundation for your container security. However, as threats evolve, you will need to revise your security measures and look for more exhaustive solutions.

Going beyond the basics with Wiz

While basic security practices form the foundation of a secure container environment, they often fall short in addressing the complex and evolving landscape of threats. Generic advice, while helpful, may not always be applicable or effective in every situation. This is where tailored, actionable insights can provide greater value, helping you navigate your specific environment's unique challenges.

At Wiz, we understand the complexities of containers and Kubernetes security. Our platform is designed to provide the tools you need to secure your container images across the lifecycle, from development to deployment and runtime.

Our highlighted features include:

  • Securing container images across the lifecycle: We provide continuous scanning of your container images for vulnerabilities, misconfigurations, and secret keys—from the moment they are built until they run in your environment.

  • Graph-based risk correlation and prioritization: Our platform correlates risks across layers and entities, providing a holistic view of your risk posture and helping you prioritize remediation efforts based on their potential impact.

  • Real-time threat detection: We monitor your runtime environment for suspicious activities and potential threats, providing real-time alerts so you can respond quickly.

  • Automatic Kubernetes Security Posture Management (KSPM): We automatically check your Kubernetes configurations against best practices, helping you identify and fix potential security issues.

Securing your container environment is a journey, not a destination. As your partner in this journey, Wiz is committed to providing you with the insights, tools, and support you need to navigate the complex landscape of container security. Take the next step in your container security journey with Wiz, and start your demo today!

What's running in your containers?

Learn why CISOs at the fastest growing companies use Wiz to uncover blind spots in their containerized environments.

Get a demo

Other security best practices you might be interested in:

Continue reading

Container Orchestration

Container orchestration involves organizing groups of containers that make up an application, managing their deployment, scaling, networking, and their availability to ensure they're running optimally.

Native Azure Security Tools

Wiz Experts Team

This blog explores the significance of security in Azure environments and provides an overview of native as well as third-party security tools available to improve an organization’s Azure security stance.

Cross-site scripting

Wiz Experts Team

Cross-site scripting (XSS) is a vulnerability where hackers insert malicious scripts inside web applications with the aim of executing them in a user’s browser.

SBOM Security

A Software Bill of Material (SBOM) is a comprehensive inventory that details every software component that makes up an application.