Implemented system components are identified.
Establish and maintain an authoritative source and repository to provide a trusted source and accountability for approved and implemented system components.
The establishment and maintenance of an authoritative source and repository includes a system component inventory of approved hardware, software, and firmware; approved system baseline configurations and configuration changes; and verified system software and firmware, as well as images and/or scripts. The authoritative source implements integrity controls to log changes or attempts to change software, configurations, or data in the repository. Additionally, changes to the repository are subject to change management procedures and require authentication of the user requesting the change. In certain situations, organizations may also require dual authorization for such changes. Software changes are routinely checked for integrity and authenticity to ensure that the changes are legitimate when updating the repository and when refreshing a system from the known, trusted source. The information in the repository is used to demonstrate adherence to or identify deviation from the established configuration baselines and to restore system components from a trusted source. From an automated assessment perspective, the system description provided by the authoritative source is referred to as the desired state. The desired state is compared to the actual state to check for compliance or deviations. [SP 80e-128] provides guidance on security configuration management, including security configuration settings and configuration change control. [IR 8011-1] provides guidance on automation support to assess system and system component configurations.