NIST 800-171 - Access Restrictions for Changes (3.4.5)

Overview:
Define, document, approve, and enforce physical and logical access restrictions associated with changes to the information system.

Action Items:
3.4.5[a]
Determine if: physical access restrictions associated with changes to the system are defined.

3.4.5[b]
Determine if: physical access restrictions associated with changes to the system are documented.

3.4.5[c]
Determine if: physical access restrictions associated with changes to the system are approved.

3.4.5[d]
Determine if: physical access restrictions associated with changes to the system are enforced.

3.4.5[e]
Determine if: logical access restrictions associated with changes to the system are defined.

3.4.5[f]
Determine if: logical access restrictions associated with changes to the system are documented.

3.4.5[g]
Determine if: logical access restrictions associated with changes to the system are approved.

3.4.5[h]
Determine if: logical access restrictions associated with changes to the system are enforced.

POTENTIAL ASSESSMENT METHODS AND OBJECTS

1
Examine: Configuration management policy; procedures addressing access restrictions for changes to the system; system security plan; configuration management plan; system design documentation; system architecture and configuration documentation; system configuration settings and associated documentation; logical access approvals; physical access approvals; access credentials; change control records; system audit logs and records; other relevant documents or records].

2
Interview: Personnel with logical access control responsibilities; personnel with physical access control responsibilities; personnel with information security responsibilities; system or network administrators].

3
Test: Organizational processes for managing access restrictions associated with changes to the system; mechanisms supporting, implementing, and enforcing access restrictions associated with changes to the system].

Related Documents (document name and content will vary by organization):
1) Configuration management policy
2) procedures addressing access restrictions for changes to the system
3) system security plan
4) configuration management plan
5) system design documentation
6) system architecture and configuration documentation
7) system configuration settings and associated documentation
8) logical access approvals
9) physical access approvals
10) access credentials
11) change control records
12) system audit logs and records
13) other relevant documents or records

Additional Guidance:
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, for example, 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 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. NIST Special Publication 800-128 provides guidance on configuration change control.