The Docker Enterprise socket must not be mounted inside any containers.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-235818	DKER-EE-002130	SV-235818r627581_rule		High

Description
The docker socket docker.sock (Linux) and \\.\pipe\docker_engine (Windows) should not be mounted inside a container, with the exception case being during the installation of Universal Control Plane (UCP) component of Docker Enterprise as it is required for install. If the docker socket is mounted inside a container it would allow processes running within the container to execute docker commands which effectively allows for full control of the host. By default, docker.sock (linux) and \\.\pipe\docker_engine (windows) is not mounted inside containers.

Description

The docker socket docker.sock (Linux) and \\.\pipe\docker_engine (Windows) should not be mounted inside a container, with the exception case being during the installation of Universal Control Plane (UCP) component of Docker Enterprise as it is required for install. If the docker socket is mounted inside a container it would allow processes running within the container to execute docker commands which effectively allows for full control of the host. By default, docker.sock (linux) and \\.\pipe\docker_engine (windows) is not mounted inside containers.

STIG	Date
Docker Enterprise 2.x Linux/UNIX Security Technical Implementation Guide	2021-03-26

Details

Check Text ( C-39037r627579_chk )
This check should be executed on all nodes in a Docker Enterprise cluster. via CLI: As a Docker EE Admin, execute the following command using a UCP client bundle: docker ps --all \| grep -iv "ucp\\|kube\\|dtr" \| awk '{print $1}' \| xargs docker inspect --format '{{ .Id }}: Volumes={{ .Mounts }}' \| grep -i "docker.sock\\|docker_engine" If the Docker socket is mounted inside containers, this is a finding.

Check Text ( C-39037r627579_chk )

This check should be executed on all nodes in a Docker Enterprise cluster.

via CLI:

As a Docker EE Admin, execute the following command using a UCP client bundle:

docker ps --all | grep -iv "ucp\|kube\|dtr" | awk '{print $1}' | xargs docker inspect --format '{{ .Id }}: Volumes={{ .Mounts }}' | grep -i "docker.sock\|docker_engine"

If the Docker socket is mounted inside containers, this is a finding.

Fix Text (F-39000r627580_fix)
When using the -v/--volume flags to mount volumes to containers in a docker run command, do not use docker.sock as a volume. A reference for the docker run command can be found at https://docs.docker.com/engine/reference/run/.