Two security issues were discovered in Kubernetes and disclosed on March 23, 2020 that could lead to a recoverable denial of service in a Kubernetes cluster.

In this blog I am going to explain why you should avoid exposing every tiny configuration in your SaaS application. I am going to talk about configurations that are related to SaaS deployments. This kind of deployments have the unique property that they are fully deployed and managed by either dev or ops teams.

Publishing a Kubernetes Service

In Kubernetes, a Service is an abstract way to expose an application running on a set of Pods as a network service

With Kubernetes you don’t need to modify your application to use an unfamiliar service discovery mechanism. Kubernetes gives Pods their own IP addresses and a single DNS name for a set of Pods, and can load-balance across them.

This post will describe the different ways used to publish a Kubernetes service, the risks harbored and the methods that can be applied to mitigate those risks.

The Kubernetes container-orchestration system provides a platform for automating deployments
and operations of application containers across clusters of hosts by defining resources as
manageable Objects. Some of these resources can be managed by other resources automatically
while others can be referenced through metadata fields within the object.

In the security world, one of the most established methods to identify that a system was compromised, abused or mis-configured is to collect logs of all the activity performed by the system’s users and automated services, and to analyze these logs.

What is Pod Security Policy?

The Pod Security Policy, sometimes called PSP in short, is a Kubernetes resource that allows the enforcement of policy rules during the creation phase of a Pod.
When a PodSecurityPolicy resource is created, it does nothing. In order to use it, the requesting user or target pod’s service account must be authorized to use the policy, by allowing the use verb on the policy.

While a lot of people are calling network policies the Kubernetes equivalent of a firewall, they probably wouldn’t be called network policies if that were really the case. Although network policies are comparable to security features like firewalls, they mostly pertain to rules, and therefore a more accurate comparison would be with “firewall rules” or security groups in the Cloud that are used to manage permissions.