Cis K8S V1120 2.3

CIS Kubernetes Benchmark v1.12.0 - Control 2.3

Profile Applicability

• Level: 1 - Master Node

Description

Do not use self-signed certificates for TLS.

Rationale

etcd is a highly-available key value store used by Kubernetes deployments for persistent storage of all of its REST API objects. These objects are sensitive in nature and should not be available to unauthenticated clients. You should enable the client authentication via valid certificates to secure the access to the etcd service.

Impact

Clients will not be able to use self-signed certificates for TLS.

Audit Procedure

Run the following command on the etcd server node:

ps -ef | grep etcd

Verify that if the --auto-tls argument exists, it is not set to true.

Remediation

Edit the etcd pod specification file /etc/kubernetes/manifests/etcd.yaml on the master node and either remove the --auto-tls parameter or set it to false.

--auto-tls=false

Default Value

By default, --auto-tls is set to false.

References

1. https://coreos.com/etcd/docs/latest/op-guide/security.html
2. https://kubernetes.io/docs/admin/etcd/
3. https://coreos.com/etcd/docs/latest/op-guide/configuration.html#auto-tls

CIS Controls

Profile

Level 1 - Master Node (Automated)