Industry vendors today emphasize security and isolation concerns for containers as a top priority, even though they are splitting their applications into services and microservices. Strategies for maintaining container security include reducing the attack surfaces in container images, avoiding public container images, and implementing role-based access controls (RBAC).
Using smartphones as an example, a secure container might be a logical area of the smartphone that contains corporate applications and data that are isolated from the owner’s apps and personal data. A dual persona approach is used in mobile device management (MDM) to manage secure containers.
Unlike files, containers are immutable. As a result, it is necessary to update the container image every time the application or microservice is modified and to launch a new container every time it is deployed. It is essential that continuous monitoring, observability, and security are maintained in this type of environment which is highly dynamic.
Integrating container security into the development cycle should be a continuous process. In addition to mitigating risk and reducing vulnerabilities across a dynamic and complex attack surface, you can leverage the power of security as part of your continuous deployment cycle.
Automation of manual touch points is essential for ensuring efficiency. In addition to developing, this also includes maintaining and operating the underlying infrastructure. You should, for instance, protect the build pipeline container images, the runtime host, your chosen platform, and all layers of your application.
Common mistakes to avoid:
Take security for granted – Containers are widely recognized as an innovative technology that requires new security methods. However, certain safety principles will continue to apply. For example, all systems should be patched and up to date, including the operating system and container runtime.
Tool and environment enhancements and configuration flaws – The container orchestration platform offers several unique security features. However, it must be properly configured for each environment to ensure security. Do not perform security configurations with platform default settings. For example, if you give a container only the permissions it needs to run the container the first time you run it in production, you may not be able to track the state of your application and environment. You may be at significant risk if this happens and the problem is not detected in time. It is especially important for highly distributed systems that span multiple clouds and on-premises infrastructure. You must ensure monitoring, logging, and testing are correctly configured. It will minimize the number of unknown vulnerabilities and reduce other blind spots. Security bugs at all stages of the
CI / CD pipeline– do not ignore the rest of the software development pipeline. Implement security early in the development cycle. It often requires consistent application of tools and policies related to the entire channel and changes as needed.
Popular Container Security Platforms
a. Docker Security
Docker is a popular open-source container engine. Automation and containerization of DevOps took off with Docker, but at the same time opened new attack surfaces. To secure Docker, you need to harden several layers:
Container images – Scan images for vulnerabilities before using them to create Docker containers.
Containers – Monitor containers at runtime to identify security issues and unusual traffic that could indicate an attack.
Docker Daemon – Ensure that the daemon running containers on host computers is configured securely.
Hosts – Secure the hosts running containers, make sure they are configured securely and do not grant excessive privileges to containers.
Overlays and APIs – Ensure that the mechanisms used by containers to communicate are secure and authenticated.
Storage Systems – Protect any storage system that containers have access to prevent unauthorized access.
b. Kubernetes Security
Kubernetes lets you manage open-source containers. Specifying a policy allows the platform to automatically apply default operational and security settings. Container security and quality standards are automatically enforced by registries and regulators. These standards apply before and during migration to the environment. Kubernetes provides security, but it is not secure by default. Standards like the Kubernetes CIS Benchmark help you understand how to set up Kubernetes securely. We recommend that you apply your security configuration as you continuously deploy new clusters.
c. Securing the Container Stack
A container stack typically consists of container images, containers, a container engine (Docker), container runtime(s), registries, hosts, and orchestrators. The following are several potential risks affecting the stack, and techniques that can help you overcome them.
Securing Container Images
Container images are just as likely to have vulnerabilities as any legacy code. To ensure that you are not introducing critical issues into the production environment, you should scan images for vulnerabilities and compliance issues. Vulnerability scanning tools produce a software bill of materials (BOM), which can help identify out-of-date or unwanted software libraries, malicious software (malware), and embedded secrets. You can then correlate risk with individual image layers to ensure you create your images safely.
Configuration drift (unplanned gradual changes to configuration over time) can be a major problem for containers. Scanned images may pass vulnerability and compliance checks today but may not be secure in the future. New threat data can reveal vulnerabilities in previously considered safe components. You must constantly monitor all your images and containers to avoid this problem.
Securing Container Runtimes
The container runtime is considered one of the most difficult components to secure. Traditional security technologies are not designed to monitor running containers, so these tools do not provide information about containers and do not provide a solid foundation for simulating secure container environments. I cannot do it. To secure your containers, you must set the container environment’s task baseline to normal security. This helps to detect and prevent anomalies and potential attacks. Runtime security should focus on application layer security, not network security.
Securing Container Registries
Management stacks are used to help coordinate the deployment of containers. Usually, a privacy container registry of some kind, which is such as Amazon ECS, and an orchestrator of containers (Kubernetes) are required to ensure data privacy.
Container registries simplify the sharing of containers. This helps teams build on each other’s work. However, these packaging containers should be protected with automated scanners that ensure that all packaging containers meet basic strengthening and protection standards.
Automated scanners check each container for known malware, vulnerabilities, and exposed secrets. Before making the container registry accessible, the check should run to reduce issues downstream.
Secure cloud services or hardened systems are the best ways to ensure your registry is protected. You need to adopt strong role-based access control (RBAC) when using cloud services and factor in the shared responsibility model of the cloud.
Securing Host Machines
Primitive implementations to secure container host machines:
Choose a befitting operating system. Ideally, we recommend a distributed operating system that is specifically optimized for running containers. Protect your operating system. Implement security measures to protect the operating system. For example, if you use a standard Linux or Microsoft Windows distribution, you may need to disable or remove unwanted services. Add a security and monitoring layer. These tools help ensure that your host is functioning correctly.
It is common for containers to interact with other containers and resources in production. Intrusion prevention systems can monitor and secure this type of internal traffic. Nevertheless, you should not deploy small numbers of large traditional IPS (Intrusion Prevention System) engines. It is better to implement the IPS on each host. As a result, all traffic can be monitored effectively without affecting performance.
Overview of Secure Image Development
Scanning the image is particularly important, but it is not enough. Make sure image security is shifted to the left, do not use insecure pictures in the first place, and make sure your new image does not contain any vulnerable components. Here are some steps to improve the security of your container images early in the development process.
a. Secure Code Running in Containers
It is intended that containers run software applications. Open source and proprietary code will typically be combined in these applications. Secure images require secure code, which is a critical aspect of securing images.
A variety of automated tools are available that can help you scan your code for vulnerabilities: Software Composition Analysis (SCA) can help discover vulnerabilities in open source components Static Application Security Testing (SAST) can scan your proprietary code for security flaws, bugs, and code quality issues Dynamic Application Security Testing (DAST) can help you test the application at runtime to discover exploitable vulnerabilities It is important to have these or similar tools as a mandatory step in your CI/CD pipeline, to ensure that all code you add to a container image is known to be safe.
b. Use Minimal Base Images
The container image is most often derived from the base image (the FROM line of the Docker File). When choosing a base image, you can choose from many public images (fewer features, components, and dependencies). Choosing a minimalist image can reduce the attack surface in the first place. It also improves resource utilization and reduces container weight. Think about the overhead of running a base image in hundreds or thousands of containers.
c. Use Trusted Images
Do not use container images from unknown publishers in public repositories. There are several sources of trusted images where you can have some confidence that the image is free of vulnerabilities and has not been modified by an attacker. For example, Official Docker Hub images are curated by Docker experts and reviewed for features and security. The Docker Verified Publishers badge indicates that the image is high quality and directly supported by Docker affiliates. For example, MySQL images are maintained now by Oracle. You can use a notary public or similar tool to verify that the image is signed by the trustee and has not been altered.
d. Be Aware of Container Image Layers
In a Docker File, you start from a base image and add additional components needed for your containers to function. You do this using RUN, COPY and ADD commands. Technically, each of these commands adds another layer to the container image, and each layer creates a new attack surface.
It is essential to be aware of the layers you want to add to your container and mitigate security risks using the following guidelines:
Make sure each layer accurately adds the tools needed for the relevant phases of the development lifecycle.
Ensure that the tools or components added to these middle tiers are using the latest version and are free of security vulnerabilities.
Most tools are only needed during the development and testing stages. Please delete it in the production environment. The best way to do this is to use a multi-level build.
Container Security Solutions
In the beyond few years, devoted safety answers have emerged that may assist stable containerized environments. Here are a few of the typically used varieties of box safety answers:
Tools that may reveal bins through runtime to discover malicious site visitors, misconfigurations, and vulnerabilities brought over time.
Tools that may test photos for acknowledged safety vulnerabilities. These gear should combine into the CI/CD toolchain and permit the scanning of box photos through the development, testing, and manufacturing stages.
A devoted factor that regulates site visitors to and from a box and site visitors on outside networks and legacy applications. Container firewalls normally run as “add-ons” with box workloads.
A device that permits you to install micro-segmentation to outline safety regulations that decide which customers or gadgets can get admission to bins, and to isolate vital workloads from the relaxation of your network.
Container protection techniques’ goal is to restrict what box root customers can do outdoor the box. It is essential to save you unauthorized entry to software programming interfaces (APIs) in addition to hosts and different back-give-up structures even though a maximum of the box protection strategies limit entry to those structures and hosts. It may be tough to pick the proper box tool, particularly while huge protection and DevOps groups proportion obligation for containerized applications. For example, the choice for whether to apply Trend Micro or Twistlock might also additionally boil right all the way down to whether the patron prefers to have box protection by a characteristic set of greater complete protection facts and occasion management (SIEM) product or stay a committed product this is the only consciousness of the safety vendor’s expertise.
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If you have any queries about Containers, security tools, or Kubernetes security, drop them in the comment section and I will get back to you quickly.
Pranav Awasthi is a Research Associate (Migration, Infra, and Security) at CloudThat. He completed his Bachelor of Engineering degree in Computer Science and completed various certifications in multi-cloud such as AWS, Azure, and GCP. His area of interest lies in Cloud Architecture and Security, Application Security, Red teaming, and Penetration Testing. Apart from professional interests. He likes to spend some time learning new generation techs and tools also reading books and playing sports.