Control: 2.5 Ensure insecure registries are not used

Description

Docker considers a private registry either secure or insecure. By default, registries are considered secure.

A secure registry uses TLS. A copy of registry's CA certificate is placed on the Docker host at /etc/docker/certs.d/<registry-name>/directory. An insecure registry is one which does not have a valid registry certificate, or one not using TLS. Insecure registries should not be used as they present a risk of traffic interception and modification. Additionally, once a registry has been marked as insecure commands such as docker pull, docker push, and docker search will not result in an error message and users may indefinitely be working with this type of insecure registry without ever being notified of the risk of potential compromise.

Remediation

You should ensure that no insecure registries are in use.

Default Value

By default, Docker assumes all, but local, registries are secure.