# Source: https://docs.datadoghq.com/security/default_rules/4kk-m7s-ur6.md

---
title: etcd servers should make use of TLS encryption for client connections
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > OOTB Rules > etcd servers should make use of TLS
  encryption for client connections
---

# etcd servers should make use of TLS encryption for client connections
Classification:complianceFramework:cis-kubernetesControl:1.2.29 
## Description{% #description %}

etcd should be configured to make use of TLS encryption for client connections.

## Rationale{% #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{% #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.

## Remediation{% #remediation %}

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{% #impact %}

TLS and client certificate authentication must be configured for etcd.

## Default value{% #default-value %}

By default, `--etcd-certfile` and `--etcd-keyfile` arguments are not set.

## References{% #references %}

1. [https://kubernetes.io/docs/admin/kube-apiserver/](https://kubernetes.io/docs/admin/kube-apiserver/)
1. [https://coreos.com/etcd/docs/latest/op-guide/security.html](https://coreos.com/etcd/docs/latest/op-guide/security.html)

## CIS controls{% #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