Navigating Risks and Solutions of Container Security

The virtual environment operates on the host operating system, with the container supporting the isolation of the guest OS and its applications. A container encompasses a unique set of files, including all dependencies required by the application it hosts: Code, libraries, tools, and settings. These components are bundled into a distinct image executed by the kernel. Docker is currently the most widely used kernel for containerization.

Container virtualization focuses on segregating and isolating processes. Since containers share the same kernel, excluding the operating system from the process is impossible. Users may interact with a general-purpose OS, which is not originally designed for container virtualization. This makes it crucial to continuously monitor the operating system. It is important to update the host OS kernel regularly, as exploiting vulnerabilities in the host’s kernel is a common method for breaking out of the container and accessing the host.

Container and Virtual Machine Security Differences

Like any technology, containers have evolved and been adopted by large businesses over time. Initially, they allowed developers and administrators to “experiment” on the same server more efficiently than with virtualization. Containerization virtualizes the operating system rather than the hardware, making containers significantly lighter and faster to create. This means they can be deployed quickly and have shorter lifespans. Applications also launch faster in containers. However, this convenience also brought complexity to the infrastructure and introduced new security threats.

Customers are more interested in the business applications they need to run than the actual underlying technology; containers or virtual machines. From a cybersecurity perspective, it is important to emphasize the inherent differences in how containers and virtual machines manage resources and isolate processes.

Containers share the host system’s kernel, while virtual machines include a full copy of an operating system, offering stronger isolation at the cost of increased overhead. This fundamental difference impacts security strategies: containers require rigorous management of images and runtime environments to avoid vulnerabilities, whereas virtual machines might focus more on perimeter defenses and internal segmentation.

Adding an orchestrator like Kubernetes increases the attack surface. While Kubernetes offers benefits, it also introduces new threats due to potential misconfigurations, such as inadequate segmentation or improper access control.

In practice, securing containers involves managing image provenance, scanning for vulnerabilities and enforcing strict runtime policies. Conversely, securing virtual machines often involves traditional network defenses and endpoint protection strategies.

It is worth noting that attackers are shifting focus from exploiting traditional software vulnerabilities to targeting configuration flaws. Risks also involve compromising a network node, where attackers can access all containers. If a compromised host contains confidential data, it risks data leakage. Additionally, an attacker could exploit the resource to run malicious activities, including crypto mining.

Container Security Tools and Techniques

To protect the environment and developers, employing a vulnerability scanner, auditing the tools used for builds, and signing containers post-build with an immutable, verifiable signature are vital steps. Additionally, it is important to periodically scan images for vulnerabilities.

However, it is important to remember that cyber threats evolve rapidly, and a determined hacker can often bypass a scanner. You could run a scan one day and find no vulnerabilities, only to discover several critical ones the very next day.

Companies must adhere to strict security policies and container security scanning best practices. This includes proper access rights management, maintaining a registry of trusted applications, traffic monitoring, and proper secrets management.

Consistent safety standards, uniform configurations, and the use of standardized tools are essential for promoting a platform approach. While vendors aim for the integration of various products, customers’ developers frequently favor comprehensive solutions from a single provider for better coherence and integration.

One often overlooked aspect is the security of the container orchestration platform itself, like Kubernetes. Ensuring the security of the orchestration layer is as critical as securing the containers it manages. Implementing role-based access control (RBAC), network policies, and securing the control plane and worker nodes can significantly reduce the attack surface. The principle of least privilege should be applied consistently. This means granting minimal permissions necessary for a container or a service to perform its intended function.

Businesses should also consider incorporating security into their continuous integration and continuous deployment (CI/CD) pipelines. This includes automated security scanning of container images in the build phase, employing static and dynamic application security testing (SAST/DAST) tools, and ensuring that only secure, compliant images are deployed to production.

Given the specific nature of containers, logging and monitoring pose unique challenges. Businesses should invest in tools and practices that can aggregate logs from containers, monitor container activity in real-time, and provide alerts on suspicious behavior. This level of observability is essential for identifying and responding to security incidents in a timely manner.

Network segmentation within containerized environments is another critical area. Given that containers are often dynamically deployed, traditional network-based security controls may not be sufficient. Implementing microsegmentation and enforcing policies based on container behavior and communication patterns can provide more granular control and visibility, reducing the risk of lateral movement within the network.

Employees’ Role in Container Security

The cybersecurity department usually manages container security, though the IT department often plays a role as well. Nowadays, there is a trend towards having dedicated engineers within IT/IS departments focus solely on container security.

Well-trained employees are crucial for safety. Vendors often provide training to enhance internal skills, but this should be an ongoing effort. Companies should adopt a zero-trust approach while also setting clear “red lines” on strictly forbidden actions.

Poorly configured or unchecked security measures can hinder developers, slow product development, and impede business progress. Sometimes, customers may temporarily turn off security measures, weighing between maintaining security and addressing immediate challenges.

Safety is a shared responsibility. If an application gets hacked, both developers and security specialists are accountable. It is clear that successful outcomes can be achieved only through collaborative and systematic efforts.

Final Thoughts

The containerization market is expanding, with a variety of solutions emerging and increasing demands for information security. A positive development is the integration with traditional security operations centers (SOCs). Moreover, tools for additional load management are becoming more accessible.

New infrastructures come with specific vulnerabilities; applications in container environments are prone to attacks, and confidential data on the host could be at risk. Monitoring host OS updates and adjusting access rights are essential measures.

Vendors provide both standalone tools, like scanners, and holistic solutions for securing container environments. Employee training is a crucial element, and a comprehensive protection strategy is essential, encompassing a wide range of practices to address and mitigate as many vulnerabilities as possible.

Alex Vakulov

Alex Vakulov is a cybersecurity researcher with over 20 years of experience in malware analysis. Alex has strong malware removal skills. He is writing for numerous tech-related publications sharing his security experience.

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