Requirement text: CM.3.067: Define, document, approve, and enforce physical and logical access
restrictions associated with changes to organizational systems.
DISCUSSION FROM SOURCE: DRAFT NIST SP 800-171 R2
Any changes to the hardware, software, or firmware components of systems can potentially
have significant effects on the overall security of the systems. Therefore, organizations
permit only qualified and authorized individuals to access systems for purposes of initiating
changes, including upgrades and modifications. Access restrictions for change also include
software libraries. Access restrictions include physical and logical access control
requirements, workflow automation, media libraries, abstract layers (e.g., changes
implemented into external interfaces rather than directly into systems), and change
windows (e.g., changes occur only during certain specified times). In addition to security
concerns, commonly-accepted due diligence for configuration management includes access
restrictions as an essential part in ensuring the ability to effectively manage the
configuration.
CMMC CLARIFICATION
Define, identify, and document qualified individuals authorized to have access and make
physical and logical changes to the organization’s hardware, software, software libraries or
firmware components. Control of configuration management activities may involve:
• physical access control which prohibits unauthorized users from gaining physical
access to an asset (e.g., requiring a special key card to enter a server room);
• logical access control which prevents unauthorized users from logging onto a system
to make configuration changes (e.g., requiring specific credentials for modifying
configuration settings, patching software, or updating software libraries);
• workflow automation in which configuration management workflow rules define
human tasks and data or files are routed between people authorized to do
configuration management based on pre-defined business rules (e.g., passing an
electronic form to a manager requesting approval of configuration change made by
an authorized employee);
• an abstraction layer for configuration management that requires changes be made
from an external system through constrained interface (e.g., software updates can
only be made from a patch management system with a specific IP address); and
• utilization of a configuration management change window (e.g., software updates are
only allowed between 8:00 AM and 10:00 AM or between 6:00PM and 8:00PM).
Example 1
You are in charge of IT operations in your organization responsible for configuration
management. You need to add an additional network storage appliance to a server farm.
However, all of your organization's servers have been consolidated into a single data center
that has locked doors. To gain access to that data center, you request and are granted a key
card which allows you to enter the data center and modify the hardware configuration.
Example 2
You are responsible for patching your organization's software as soon as new versions are
released or when emergency patching is required. You configure the patch management
system to push patches to all endpoints in the enterprise as soon as a patch or update is
available, has been confirmed to have been received from the proper source, and has been
validated.
References
• NIST SP 800-171 Rev 1 3.4.5
• CIS Controls v7.1 2.5, 2.7, 2.8, 2.9, 4.3, 11.1, 11.3, 11.7
• NIST CSF v1.1 PR.IP-1
• CERT RMM v1.2 TM:SG4.SP1
• NIST SP 800-53 Rev 4 CM-5
• UK NCSC Cyber Essentials