Details

Limit the rate at which the API server accepts requests.

Rationale:

Using EventRateLimit admission control enforces a limit on the number of events that the API Server will accept in a given time slice. A misbehaving workload could overwhelm and DoS the API Server, making it unavailable. This particularly applies to a multi-tenant cluster, where there might be a small percentage of misbehaving tenants which could have a significant impact on the performance of the cluster overall. Hence, it is recommended to limit the rate of events that the API server will accept.

Note: This is an Alpha feature in the Kubernetes 1.15 release.

Impact:

You need to carefully tune in limits as per your environment.

Solution

Follow the Kubernetes documentation and set the desired limits in a configuration file.
Then, edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml and set the below parameters.

–enable-admission-plugins=…,EventRateLimit,…
–admission-control-config-file=

Default Value:

By default, EventRateLimit is not set.

Supportive Information

The following resource is also helpful.

• https://workbench.cisecurity.org/files/3371

This security hardening control applies to the following category of controls within NIST 800-53: Access Control.This control applies to the following type of system Unix.

References

• 800-53|AC-6
• CSCv6|8.4
• CSCv7|8.3

Source

• Tenable.com/audits