DKER-EE-003590 - Content Trust enforcement must be enabled in Universal Control Plane (UCP) in Docker Enterprise.

Information

The UCP and Docker Trusted Registry (DTR) components of Docker Enterprise can be used in concert to perform an integrity check of organization-defined software at startup. In the context of Docker Enterprise, software would be analogous to Docker images that have been pulled from trusted or untrusted sources. Docker Hub is the most common upstream endpoint for retrieving Docker images. However, only 'Docker Certified' images on Docker Hub are considered trusted and come with SLAs and trusted signatures from their respective vendors. All other images from Docker Hub or other external registries must be carefully inspected and triaged prior to use. Docker Content Trust (DCT) provides for content integrity checking mechanisms on Docker images. DCT can be combined with LDAP, Docker Trusted Registry (DTR) and Universal Control Plane (UCP) to enforce image signatures from users/accounts in LDAP. Therefore, to meet the requirements of this control, it is imperative that UCP has LDAP integration enabled and that content trust enforcement is enabled and properly configured.

An operational requirement of this control is that of the required use of an established continuous integration and deployment workflow that effectively dictates exactly what software is allowed to run on UCP.

NOTE: Nessus has not performed this check. Please review the benchmark to ensure target compliance.

Solution

This fix only applies to the UCP component of Docker Enterprise.

Enable Content Trust enforcement in UCP.

via UI:

In the UCP web console, navigate to 'Admin Settings' | 'Docker Content Trust' and check the box next to 'Run only signed images'. Set the appropriate Orgs and Teams that images must be signed by in the dropdown that follows to match that of the organizational policies.

via CLI:

Linux: As a Docker EE Admin, execute the following commands on a machine that can communicate with the UCP management console. Replace [ucp_url] with the UCP URL, [ucp_username] with the username of a UCP administrator and [ucp_password] with the password of a UCP administrator:

AUTHTOKEN=$(curl -sk -d '{'username':'[ucp_username]','password':'[ucp_password]'}' https://[ucp_url]/auth/login | jq -r .auth_token)
curl -sk -H 'Authorization: Bearer $AUTHTOKEN' https://[ucp_url]/api/ucp/config-toml > ucp-config.toml

Open the 'ucp-config.toml' file, set the 'require_content_trust' entry under the '[trust_configuration]' section to 'true'. Save the file.

Execute the following commands to update UCP with the new configuration:

curl -sk -H 'Authorization: Bearer $AUTHTOKEN' --upload-file ucp-config.toml https://[ucp_url]/api/ucp/config-toml

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Docker_Enterprise_2-x_Linux-Unix_V2R2_STIG.zip

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-7(5)(b), CAT|II, CCI|CCI-001774, Rule-ID|SV-235838r961479_rule, STIG-ID|DKER-EE-003590, STIG-Legacy|SV-104847, STIG-Legacy|V-95709, Vuln-ID|V-235838

Plugin: Unix

Control ID: c383fc351f266c9a6fc71871dd7852eb6ca087753b8af4c466a36eb65c9a0951