Etcd should use TLS encryption for peer connections
Set up the kubernetes integration.
Description
Etcd should be configured to make use of TLS encryption for peer connections.
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 encrypted in transit and also amongst peers in the etcd clusters.
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 the --peer-cert-file and --peer-key-file arguments are set as appropriate.
Follow the etcd service documentation and configure peer TLS encryption as appropriate for your etcd cluster. Then, edit the etcd pod specification file /etc/kubernetes/manifests/etcd.yaml on the master node and set the below parameters:
--peer-cert-file=</path/to/peer-cert-file>
--peer-key-file=</path/to/peer-key-file>
Impact
Etcd cluster peers would need to set up TLS for their communication.
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 communication over TLS is not configured.
References
- https://coreos.com/etcd/docs/latest/op-guide/security.html
- https://kubernetes.io/docs/admin/etcd/
CIS controls
Version 6.14.2 Encrypt All Sensitive Information Over Less-trusted Networks - All communication of sensitive information over less-trusted networks should be encrypted. Whenever information flows over a network with a lower trust level, the information should be encrypted.
Version 7.14.4 Encrypt All Sensitive Information in Transit - Encrypt all sensitive information in transit.
