3.1.1
AC.L1-3.1.1 · Level 1 + 2
Limit system access to authorized users, processes acting on behalf of authorized users, and…
NIST SP 800-171 Rev 2 · §3.1.1
Limit system access to authorized users, processes acting on behalf of authorized users, and devices (including other systems).
Assessment objectives
3.1.1[a]
authorized users are identified.
Examine
[SELECT FROM: Access control policy; procedures addressing account management; security plan; system design documentation; system configuration settings and associated documentation; list of active system accounts and the name of the individual associated with each account; list of conditions for group and role membership; notifications or records of recently transferred, separated, or terminated employees; list of recently disabled system accounts along with the name of the individual associated with each account; access authorization records; account management compliance reviews; system monitoring records; system audit logs and records; other relevant documents or records; list of devices and other systems authorized to connect to organizational systems].
Interview
[SELECT FROM: Personnel with account management responsibilities; system or network administrators; personnel with information security responsibilities].
Test
[SELECT FROM: Organizational processes for managing system accounts; mechanisms for implementing account management].
3.1.1[b]
processes acting on behalf of authorized users are identified.
Examine
[SELECT FROM: Access control policy; procedures addressing account management; security plan; system design documentation; system configuration settings and associated documentation; list of active system accounts and the name of the individual associated with each account; list of conditions for group and role membership; notifications or records of recently transferred, separated, or terminated employees; list of recently disabled system accounts along with the name of the individual associated with each account; access authorization records; account management compliance reviews; system monitoring records; system audit logs and records; other relevant documents or records; list of devices and other systems authorized to connect to organizational systems].
Interview
[SELECT FROM: Personnel with account management responsibilities; system or network administrators; personnel with information security responsibilities].
Test
[SELECT FROM: Organizational processes for managing system accounts; mechanisms for implementing account management].
3.1.1[c]
devices (including other systems) authorized to connect to the system are identified.
Examine
[SELECT FROM: Access control policy; procedures addressing account management; security plan; system design documentation; system configuration settings and associated documentation; list of active system accounts and the name of the individual associated with each account; list of conditions for group and role membership; notifications or records of recently transferred, separated, or terminated employees; list of recently disabled system accounts along with the name of the individual associated with each account; access authorization records; account management compliance reviews; system monitoring records; system audit logs and records; other relevant documents or records; list of devices and other systems authorized to connect to organizational systems].
Interview
[SELECT FROM: Personnel with account management responsibilities; system or network administrators; personnel with information security responsibilities].
Test
[SELECT FROM: Organizational processes for managing system accounts; mechanisms for implementing account management].
3.1.1[d]
system access is limited to authorized users.
Examine
[SELECT FROM: Access control policy; procedures addressing account management; security plan; system design documentation; system configuration settings and associated documentation; list of active system accounts and the name of the individual associated with each account; list of conditions for group and role membership; notifications or records of recently transferred, separated, or terminated employees; list of recently disabled system accounts along with the name of the individual associated with each account; access authorization records; account management compliance reviews; system monitoring records; system audit logs and records; other relevant documents or records; list of devices and other systems authorized to connect to organizational systems].
Interview
[SELECT FROM: Personnel with account management responsibilities; system or network administrators; personnel with information security responsibilities].
Test
[SELECT FROM: Organizational processes for managing system accounts; mechanisms for implementing account management].
3.1.1[e]
system access is limited to processes acting on behalf of authorized users.
Examine
[SELECT FROM: Access control policy; procedures addressing account management; security plan; system design documentation; system configuration settings and associated documentation; list of active system accounts and the name of the individual associated with each account; list of conditions for group and role membership; notifications or records of recently transferred, separated, or terminated employees; list of recently disabled system accounts along with the name of the individual associated with each account; access authorization records; account management compliance reviews; system monitoring records; system audit logs and records; other relevant documents or records; list of devices and other systems authorized to connect to organizational systems].
Interview
[SELECT FROM: Personnel with account management responsibilities; system or network administrators; personnel with information security responsibilities].
Test
[SELECT FROM: Organizational processes for managing system accounts; mechanisms for implementing account management].
3.1.1[f]
system access is limited to authorized devices (including other systems).
Examine
[SELECT FROM: Access control policy; procedures addressing account management; security plan; system design documentation; system configuration settings and associated documentation; list of active system accounts and the name of the individual associated with each account; list of conditions for group and role membership; notifications or records of recently transferred, separated, or terminated employees; list of recently disabled system accounts along with the name of the individual associated with each account; access authorization records; account management compliance reviews; system monitoring records; system audit logs and records; other relevant documents or records; list of devices and other systems authorized to connect to organizational systems].
Interview
[SELECT FROM: Personnel with account management responsibilities; system or network administrators; personnel with information security responsibilities].
Test
[SELECT FROM: Organizational processes for managing system accounts; mechanisms for implementing account management].
What we look for in practice
The following are placeholder notes that should be refined based on practice experience.
What assessors look for in practice. Documented evidence that this control is implemented across all CUI-handling systems within scope. Specific artifacts vary, but expect requests for written procedures, system configurations, and operational records demonstrating the control is active.
Common failure patterns. Typical issues include incomplete documentation, inconsistent implementation across systems, and missing periodic review records. Refine this section as your practice accumulates direct assessment experience.
Strong evidence looks like. Formal policy referencing this control, technical configurations demonstrating enforcement, periodic review logs with sign-off, and procedures for handling exceptions.
Scoring and POA&M context. 5-point control under the DoD Assessment Methodology. Highest scoring impact — treat as a foundational requirement. Not POA&M-eligible — must be implemented at assessment time.