NIST 800-171 3.1.12 (AC.L2-3.1.12): Remote Access Control

Monitor and control remote access sessions.

NIST SP 800-171 Rev. 2, requirement 3.1.12

CMMC Level 2 practice AC.L2-3.1.12Published 2026-11-11

What 3.1.12 means in practice

Decide which kinds of remote access you allow, such as VPN, a remote desktop gateway or cloud management consoles, and permit only those. Each remote session is controlled (who may connect, from which device and from where) and monitored, with logs that show who connected, when and from what address.

SPRS points and the CMMC POA&M

CMMC Level 2 practice: AC.L2-3.1.12
SPRS points: 5 points. When it is not met, the DoD Assessment Methodology subtracts 5 from the score of 110.
CMMC POA&M: Not allowed. It is worth 5 points, and 32 CFR 170.21(a)(2)(ii) admits only requirements worth 1 point, with one exception: 3.13.11 when encryption is used but not FIPS validated.
Scoring note: If the system permits no remote access, mark Met: Annex A subtracts nothing. Keep a policy and procedure that stops it being turned on by accident: without one, a Medium assessment takes 1 point.

Sources: NIST SP 800-171 DoD Assessment Methodology, version 1.2.1 (June 24, 2020), Annex A; 32 CFR 170.21, Plan of Action and Milestones requirements.

What an assessor checks for 3.1.12

NIST SP 800-171A gives 4 determination statements for 3.1.12, each found satisfied or other than satisfied. Determine if:

3.1.12[a] remote access sessions are permitted.
3.1.12[b] the types of permitted remote access are identified.
3.1.12[c] remote access sessions are controlled.
3.1.12[d] remote access sessions are monitored.

NIST SP 800-171A (June 2018), assessment objectives for 3.1.12

Evidence that shows 3.1.12 is met

A list of the permitted remote access methods and who may use them.
VPN or gateway configuration that limits remote access to those methods.
Remote access logs for a recent period, with user, time and source address.
Network rules that block remote administration ports from the internet.

How PolicyCortex gathers the evidence

PolicyCortex reads this evidence with the collectors below, read only, and grades 3.1.12 from it. Each line says what the product checks.

Azure: Network security groups. Checks that network security group rules open remote access ports (RDP and SSH) only to authorized sources.

Related pages

Calculator: SPRS score calculator: mark 3.1.12 and the other 109 requirements and see the score.
Sample package: Sample package: an SSP, a POA&M and an evidence chain the product generated from demonstration data.
Family: All 22 Access Control requirements (3.1).
Previous: 3.1.11: Session Termination
Next: 3.1.13: Remote Access Encryption
All requirements: All 110 NIST SP 800-171 requirements, by family.

Related records

Guides and articles describe the work. The evidence that work produces is described in three proof pages, the architecture page, and the two pages on authorization.

proof.state: Proof of State. What the environment was, as of a date someone else picks: point-in-time records, content hashed and chained.
proof.change: Proof of Change. Who or what altered the environment, under what authority, with before and after state hashes.
proof.agency: Proof of Agency. What a machine was permitted to do before it acted, what it did, and what would have stopped it.
architecture: Architecture. How the chain is built and where the evidence is stored in each delivery mode.
authorization: Continuous ATO. How an authorizing official's decision is recorded with its package, and how the authorized system is checked against it every hour.
baseline: NIST SP 800-53. The Low, Moderate and High baselines as evidence, with the SSP, SAR and POA&M generated from one record.