Cis Docker V170 7.5

---
name: cis-docker-v170-7.5
description: "Ensure that swarm manager is run in auto-lock mode"
category: cis-docker
version: "1.7.0"
author: cyberstrike-official
tags: [cis, docker, swarm, auto-lock, encryption]
cis_id: "7.5"
cis_benchmark: "CIS Docker Benchmark v1.7.0"
tech_stack: [docker]
cwe_ids: []
chains_with: []
prerequisites: []
severity_boost: {}
---

# CIS Docker Benchmark v1.7.0 - Control 7.5

## Profile Applicability

- **Level:** 1
- **Type:** Manual
- **Platform:** Docker Swarm

## Description

You should review whether you wish to run Docker swarm manager in auto-lock mode.

## Rationale

When Docker restarts, both the TLS key used to encrypt communication among swarm nodes, and the key used to encrypt and decrypt Raft logs on disk, are loaded into each manager node's memory. You could protect the mutual TLS encryption key and the key used to encrypt and decrypt Raft logs at rest. This protection could be enabled by initializing the swarm with the `--autolock` flag.

With `--autolock` enabled, when Docker restarts, you must unlock the swarm first, using a key encryption key generated by Docker when the swarm was initialized.

This has benefits in a high security environment, however these should be balanced against the support issues caused by the swarm not starting automatically if, for example the host was to experience an outage.

## Impact

A swarm in auto-lock mode will not recover from a restart without manual intervention from an administrator to enter the unlock key. This may not always be desirable, and should be reviewed at a policy level.

## Audit Procedure

You should run the command below

```bash
docker info --format 'Swarm Autolock: {{ .Swarm.Cluster.Spec.EncryptionConfig.AutoLockManagers }}'
```

If the result is `true`, auto-lock mode is enable.

You could also run the command below. If a key value is returned, it means that the swarm was initialized with the `--autolock` flag. If the output is `no unlock key is set`, it means that swarm was NOT initialized with the `--autolock` flag. This should be reviewed in line with the organization's IT Security policy.

```bash
docker swarm unlock-key
```

## Remediation

If you are initializing a swarm, use the command below.

```bash
docker swarm init --autolock
```

If you want to set `--autolock` on an existing swarm manager node, use the following command.

```bash
docker swarm update --autolock
```

## Default Value

By default, the swarm manager does not run in auto-lock mode.

## References

1. https://docs.docker.com/engine/swarm/swarm_manager_locking/

## CIS Controls

**v8:**

- **3.11 Encrypt Sensitive Data at Rest**
  - Encrypt sensitive data at rest on servers, applications, and databases containing sensitive data. Storage-layer encryption, also known as server-side encryption, meets the minimum requirement of this Safeguard. Additional encryption methods may include application-layer encryption, also known as client-side encryption, where access to the data storage device(s) does not permit access to the plain-text data.

**v7:**

- **14.8 Encrypt Sensitive Information at Rest**
  - Encrypt all sensitive information at rest using a tool that requires a secondary authentication mechanism not integrated into the operating system, in order to access the information.