TLS connections between etcd peers should not use self-signed certificates
Set up the kubernetes integration.
Description
Do not use automatically generated self-signed certificates for TLS connections between peers.
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 be accessible only by authenticated etcd peers in the etcd cluster. Hence, do not use self-signed certificates for authentication.
Audit
This recommendation is applicable only for etcd clusters. If you are using only one etcd server in your environment then this recommendation is not applicable.
Run the following command on the etcd server node:
Verify that if the --peer-auto-tls argument exists, it is not set to true.
Edit the etcd pod specification file /etc/kubernetes/manifests/etcd.yaml on the master node and either remove the --peer-auto-tls parameter or set it to false.
Impact
All peers attempting to communicate with the etcd server will require a valid client certificate for authentication.
Default value
Note: This recommendation is applicable only for etcd clusters. If you are using only one etcd server in your environment then this recommendation is not applicable. By default, --peer-auto-tls argument is set to false.
References
- https://coreos.com/etcd/docs/latest/op-guide/security.html
- https://kubernetes.io/docs/admin/etcd/
- https://coreos.com/etcd/docs/latest/op-guide/configuration.html#peer-auto-tls
CIS controls
Version 6.14 Controlled Access Based on the Need to Know
Version 7.4 Controlled Use of Administrative Privileges
