With containers, you can build, deploy, scale, and integrate your applications without interruption. From the developer’s perspective, you get the efficiency and flexibility necessary for building an application that can be deployed to any operating system. From your security team’s perspective, you might be compromising the application’s security. You can think of it like storing water. You can get the cleanest, freshest water directly from an Icelandic glacier, but if you pour it into a dirty glass, you contaminate it.

For developers to secure code effectively, they should understand app container security to protect their development, testing, and runtime activities.

What is container security?

Container security consists of security technologies, policies, and processes used to protect the containerized application and its underlying infrastructure.  To secure applications, developers should monitor their containers and integrate these activities into their development processes.

When trying to secure the container and its application, you should consider the following:

• Container image and its software
• Interactions between container, host operating system, and other containers on the same host
• Host operating system
• Container network
• Storage repositories
• Container runtime environment

Typically, development and security teams implement automated tools that enable regular container environment security checks, updates, and maintenance.

Why is container security important?

Container security is critical to software supply chain security. In cloud-native development workflows, security becomes increasingly complex for various reasons, including the following:

• Protecting the production environment: Mitigate data breach and downtime risks
• Software supply chain security: Identify known vulnerabilities in base images or underlying infrastructure components
• Collaboration between DevOps and Security teams: Incorporate security checks and controls early in the software development life cycle (SDLC)
• Compliance: Secure SDLC required by most data protection laws, regulations, and industry standards

What risks do containers pose to an application’s security?

While containerized environments streamline software development, they can potentially undermine the application’s and organization’s security. Some risks that containers pose to security include:

• Expanding the attack surface: Each container becomes a potential entry point that attackers can exploit.
• Software vulnerabilities: A container’s base image or underlying infrastructure components may contain vulnerabilities that attackers can exploit.
• Data breach risks: Attackers with unauthorized access to a containerized environment can compromise customer nonpublic information (NPI) or intellectual property.
• Lateral movement: Attackers can use their unauthorized access to containers or the underlying host operating systems to help them bypass normal system access controls.
• Outdated open-source software: Container images from public repositories may not have recent security updates.

 Steps to Securing Containers

Although container security can be challenging, following some best practices enables you to protect against attackers that seek to exploit containerized applications.

1. Use trusted sources for base images

Starting with a minimal base image from a trusted source provides a secure foundation for the rest of your development process. By using a minimal base image, you include only the necessary components and libraries that your application needs. This reduces the number of potential vulnerabilities and the attack surface. Trusted sources update their base images regularly to address known security vulnerabilities, enabling you to maintain a strong security posture over time.

2. Secure code and its dependencies

To mitigate risks arising from vulnerabilities, you should:

• Identify all dependencies
• Automate vulnerability scanning to identify any vulnerabilities regularly
• Regularly update and patch dependencies in your containerized applications

3. Manage layers between the base image and code

While you might start with a minimal base image, your development process adds more layers, like tools, runtime, libraries, and your code. With container security tools, you can regularly scan images to identify and remediate any vulnerabilities. Additionally, if you use a  multi-stage build, some tools that you use during development might not be necessary once you push the application to production. While you need to monitor and maintain these during the development process, you can remove them from the production images to reduce risk.

4. Implement vulnerability management and assessment

Identifying and addressing the security vulnerabilities in your containerized environment enables you to secure your containerized environment. You should regularly scan your container images for new vulnerabilities, then remediate them as quickly as possible. Vulnerability scans can often feel overwhelming because they provide a long list of problems you must fix. However, you can use automated container-scanning tools that help you prioritize your remediation activities based on the:

• Number of reachable vulnerabilities
• Number of reachable vulnerabilities for a given severity level
• Number of unreachable vulnerabilities
• Number of unreachable vulnerabilities for a given severity level

Reachability means that attackers can use the identified vulnerability to gain unauthorized access to the containerized environment. By focusing on the vulnerabilities that attackers can exploit and prioritizing those according to severity, you can secure your containerized environment more effectively and reduce the time it takes to complete the activities.

5. Centrally manage access controls

Limiting user access according to the principle of least privilege makes it easier to identify any potential abnormal access and activity signaling malicious behavior.

Some best practices include:

• Role-based access controls (RBAC): giving users the least amount of access necessary to complete their job functions

• Multi-factor authentication (MFA): requiring users to respond to a challenge question, like using a one-time code, one-time password, or biometrics for additional verification
• Access reviews: regularly reviewing whether users have the right access

Qwiet.ai: At-a-glance container security visibility

With Qwiet.ai’s preZero platform, you can incorporate regular container scans for visibility into risks both inside and outside your code. Our container scanning uses the same methods applied through our platform so that you can quickly prioritize the fixes that you need to complete immediately and postpone others that can happen when developer hours free up. If your applications reside in Docker containers, you can use preZero to scan the contents of the container along with your app.

Try Qwiet AI’s preZero platform for free to see how it can help you secure your containerized environments today.