Kubernetes is a popular open source container orchestration tool that is taking the container market by storm. Having a container orchestration tool like Kubernetes is vital for organisations; otherwise, they would not be able to run a containerised application for production purposes. Without it, trying to manually deploy and manage containers using the command line would be almost logistically impossible on a large scale.
There are many benefits of automating tasks, such as deployment, scaling, and the overall management of containerised applications. It is crucial to understand that this same tool can cause gaping holes in your security without appropriate measures in place.
Kubernetes does not manage security
According to recent reports, over 86% of organisations manage some portion of their container workloads using Kubernetes; however, security still remains a large concern. In this same survey, over half of respondents stated that their organisation does not have an adequate investment in container security. Without a strategy in place, this can quickly cause delays in adoption of Kubernetes or serious security incidents.
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 use additional programs or third-party vendors to ensure that proper security systems are in place.
Here are some elements to consider when securing your Kubernetes containers:
- Default configurations
- Container runtime
- Host security
- Pod-to-pod communications
One of the first components to consider when securing Kubernetes containers is default configurations. All default Kubernetes configurations must be checked before use to minimise 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, most 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 rights to users who may not necessarily need the information. Leaving potentially sensitive data exposed in such a way is a huge risk, opening up confidential information to malicious users.
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 that fixed the root cause of the security issue should also be used to reconfigure the component in the environment.
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.
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 used to monitor them for security issues.
Many businesses then turn to traditional host security in this instance to detect exploits against system resources, but should the host also be compromised, it can lead to devastating consequences. Host systems must be monitored for breaches and suspicious activities to fight off vicious attacks.
By default, Kubernetes doesn’t apply network policy to each pod, which means that pods in the Kubernetes environment can talk to one another. It is advantageous for proper functioning that containers and pods talk to each other within deployments. This can, however, quickly become an easy target for cybercriminals, who just have to breach one container to then move laterally within the environment.
Associating a network policy with a pod limits its communication to defined assets, serving a role similar to firewall rules and controls.
With a majority of organisations 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.