Top 10 Container Security Best Practices

Containerized applications have grown in popularity. They are a flexible solution for deploying applications across operating systems and platforms. Yet, containerized applications also introduce risks, like vulnerable application source code, OSS container images, and runtime risks. In this article, we explain how to secure containers: which elements in a containerized architecture demand attention, challenges to overcome, best practices for securing containers throughout the SDLC, and more.

Container security is the practices and tools used to protect container architecture components against vulnerabilities and threats, so they do not become entry points into the wider system. Here are top 10 practices.

Key Components of Container Architecture to Secure

The unique characteristics of containerized environments make their security complex. Here are the key components to focus on for securing container architecture:

• • Container Images – The static file that contains the code, runtime, libraries, and settings required for running the application on the containerization platform. Container images used from external sources should be taken only from trusted and official repositories. External and internally developed images should be scanned to ensure they are vulnerability-free.
  • Container Runtime – The component that runs the container lifecycle. Runtime should always be up-to-date and patched, to ensure containers are isolated and to reduce exploitability.
  • Container Orchestrators – The components that manage deployment and interaction of containers. Kubernetes is a well-known example of an orchestrator. The orchestrator should be securely configured to protect against CVEs and minimize exploitability.
  • Network – Where containers communicate with each other. The network should be segmented and data should be encrypted to prevent lateral movement, container escape and other forms of attack, and to protect the data.
  • Host System – The component that runs container runtime and orchestration. The host system needs to be patched and hardened to minimize exploitations.

Why is Container Security Important?

The use of containers in software development and deployment has grown significantly due to their flexibility and portability. But they also increase the attack surface, since they might also introduce risks.

For example, container images available as open-source code can bring vulnerabilities or malicious code with them into the system. Or, applications in runtime can include risks that were not apparent before.

Container security encompasses the practices and tools used to protect container architecture components against vulnerabilities and threats. This helps prevent containers from becoming entry points into the wider system or the data they hold from being compromised.

Effects of Container Attacks

Container attacks can have several significant and wide-ranging effects on an organization’s IT infrastructure, security posture and operational capabilities. Here are some of the key impacts:

• Containers can be used to execute malicious code and distribute malware across the network.
• Attackers gaining access to sensitive data within containers can lead to data breaches and/or the modification and deleting of data, leading to data integrity issues.
• Successful attacks can disrupt containerized services, causing downtime and affecting business continuity.
• Attackers can use compromised containers as a stepping stone to move laterally within the infrastructure.
• The cost of detecting, responding to, and mitigating container attacks can be substantial.
• Attackers might consume internal resources, leading to performance degradation of critical applications.
• Non-compliance with data protection regulations due to a breach can result in legal repercussions and hefty fines.

Challenges in Securing Containers 

Securing containers presents a unique set of challenges due to the nature of their deployment and the environments in which they operate. Here are some key challenges:

• Containers are complicated to secure, since they are dynamic and ephemeral. This also results in lack of visibility into containers. AppSec teams need adaptive security tools and expertise in container architectures.
• Container images can be vulnerable, leading to potential breaches. This requires regular scanning for vulnerabilities.
• Containers might be misconfigured, becoming entry points for attackers. This required advanced knowledge of container configuration and implementation of the principle of least privilege.
• Attackers might compromise container images through their supply chain, like through third-party images. This requires securing and scanning components from the supply chain as well.

Container Security Best Practices 

Defending against container attacks involves a multi-layered approach, addressing security at every stage of the container lifecycle. Here are key strategies and practices to ensure robust container security:

1. Start with minimal, trusted base images only from reputable sources. Use image signing to ensure integrity and authenticity.
2. Regularly scan container images to identify vulnerable code, using tools and container scanning frameworks like Checkmarx.
3. Run containers with the least privileges necessary. Avoid running containers as the root user, and use user namespaces. Implement access controls like RBAC to restrict who can deploy and manage containers.
4. Where possible, configure containers with read-only file systems to prevent unauthorized modifications.
5. Implement network policies to control container communication and enforce segmentation.
6. Correlate pre-production and runtime data to identify exploitable vulnerabilities in running container images.
7. Regularly update and patch the host OS and container runtime to address security vulnerabilities.
8. Set resource limits (CPU, memory) to prevent denial-of-service (DoS) attacks caused by resource exhaustion.
9. Avoid storing secrets in container images. Secrets should only be stored in the dedicated manager.
10. Regularly audit your container infrastructure for compliance with security best practices and policies.

Use these practices as your container security checklist.

Container Security with Checkmarx

Checkmarx provides comprehensive containerized security throughout the SDLC, from development to runtime. We ensure that vulnerabilities in both static container images and running applications are identified and remediated early, reducing risk in production environments.

Prioritization of exploitable vulnerabilities reduces noise and builds devsec trust. This enhances the security posture and reduces potential threats in containerized environments across static images and running containerized applications.

Key Capabilities:

• Container Image Scanning – Identify vulnerabilities in static container images before deployment.
• Runtime Insights Correlation – Identify exploitable vulnerabilities based on merged pre-production and runtime data. Achieved through an integration with Sysdig.
• Filterable Views – Filter vulnerabilities by risk level and runtime usage.
• Prioritization and Remediation – Focus on high-risk vulnerabilities to streamline remediation efforts across open-source and source code and remediate with guidance.

For more details, you can request a demo.