What is Kubernetes Container Security?

Kubernetes Container Security is:

a holistic endeavor, composed of also securing Kubernetes pods, images, runtimes, hosts, and the infrastructure itself.

Kubernetes container security

Kubernetes is a popular open-source container orchestration tool that is taking the container market by storm. Having a container orchestration tool such as Kubernetes is vital for organizations, otherwise they would not be able to run a containerized application for production purposes. Without it, trying to manually deploy and manage containers using the command line would almost be logistically impossible on a large scale.

Although the benefits of automating tasks such as deployment, scaling, and the overall management of containerized applications are many, it is crucial to understand that this same tool can cause gaping holes in your security if appropriate measures are not taken.

Kubernetes does not manage security

According to recent reports, over 86% of organizations manage some portion of their container workloads using Kubernetes; however, security still remains a large concern. From this same survey, over half of respondents stated that their organization does not have an adequate investment in container security, quickly causing delays in adoption of Kubernetes or serious security incidents without a strategy in place.

Beyond basic features, such as enforcing role-based access control, Kubernetes does not offer the ability to protect applications from vulnerabilities. This is where you must utilize additional programs or third-party vendors to ensure that proper security systems are in place.

Things to consider

Here are some elements to consider when securing your Kubernetes containers: 

  • Default configurations 
  • Container runtime 
  • Images 
  • Host security 
  • Pod-to-pod communications

 

Default configurations

One of the first components to consider when securing Kubernetes containers is default configurations. All default Kubernetes configurations must be checked before using to minimize the risk that an attack within one pod would spread to other pods.

Although Kubernetes does have a specific framework for things like access control, a majority of these access-control features are not usually turned on by default. These types of controls may not be configured to enforce least-privilege policies either, giving full right to users that may not necessarily need that information. Leaving potentially sensitive data exposed in such a way is a huge risk, opening up confidential information to malicious users.

Container runtime

A container runtime is a special application that executes containers. It is important to understand that Kubernetes does not have protections in place against a runtime attack nor can it detect intrusions after they occur.

Should an active breach or a new vulnerability be detected in a running container, the entire container needs to be killed and a non-compromised version must be relaunched. Information should also be used to reconfigure the component in the environment that fixed the root cause of the security issue.

Images

Images can also make containers more vulnerable. Poorly configured images provide an easy access point for attackers to break into a network, and images that contain specific authentication keys can assist cybercriminals in further attacks.

Detecting malicious code that is inside a container image requires vulnerability scanning in registries and in production, which is not a feature of Kubernetes.

Host security

By design, Kubernetes runs containers on the servers that are assigned to it. Since the orchestration tool doesn’t have anything to do with the security of those servers, other processes must be utilized to monitor them for security issues.

Many businesses then turn to traditional host security in this instance in order to detect exploits against system resources, but should the host also be compromised, this can lead to devastating consequences. Host systems must be monitored for breaches and suspicious activities to fight off vicious attacks.

Pod-to-pod communications

By default, Kubernetes doesn’t apply network policy to each pod, which means that every pod can talk to every other pod in the Kubernetes environment. While it is advantageous for containers and pods to talk to each other within deployments for proper functioning, this can quickly become an easy target for cybercriminals who just have to breach one container in order to then move laterally within the environment.

Associating a network policy with a pod behaves like firewall rules and controls that the pod can only communicate with defined assets.

Securing Kubernetes containers

With a majority of organizations using it, ensuring Kubernetes container security is crucial to keeping networks and applications safe from breaches and malicious attacks. By successfully integrating security into each phase of the Kubernetes container lifecycle, businesses can be confident they are putting proper measures into place.

Container Security Topics