etcd servers should make use of TLS encryption for client connections
Set up the kubernetes integration.
Description
etcd should be configured to make use of TLS encryption for client 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 protected by client authentication. This requires the API server to identify itself to the etcd server using a client certificate and key.
Audit
Run the following command on the master node:
ps -ef | grep kube-apiserver
Verify that the --etcd-certfile and --etcd-keyfile arguments exist and they are set as appropriate.
Follow the Kubernetes documentation and set up the TLS connection between the apiserver and etcd. Then, edit the API server pod specification file /etc/kubernetes/manifests/kube-apiserver.yaml on the master node and set the etcd certificate and key file parameters.
--etcd-certfile=<path/to/client-certificate-file>
--etcd-keyfile=<path/to/client-key-file>
Impact
TLS and client certificate authentication must be configured for etcd.
Default value
By default, --etcd-certfile and --etcd-keyfile arguments are not set.
References
- https://kubernetes.io/docs/admin/kube-apiserver/
- https://coreos.com/etcd/docs/latest/op-guide/security.html
CIS controls
Version 6 9 Limitation and Control of Network Ports, Protocols, and Services
Version 7 9 Limitation and Control of Network Ports, Protocols, and Services
