--- title: "NIST 800-171 3.1.1 (AC.L2-3.1.1): Authorized Access" description: "NIST SP 800-171 3.1.1 Authorized Access: 5 SPRS points, not allowed on a CMMC POA&M. The text, what assessors check and the evidence." url: https://policycortex.com/nist-800-171/access-control/3.1.1 sealed: 2026-11-11 amended: 2026-11-11 register: nist-800-171/access-control/3.1.1 records: 7 digest: sha3:c4b499183b78b39dd8eddf9f9621570919e568cb757780eff2bd5188d865f66d --- # NIST 800-171 3.1.1 (AC.L2-3.1.1): Authorized Access NIST 800-171 / Access Control / 3.1.1 "Limit system access to authorized users, processes acting on behalf of authorized users, and devices (including other systems)." ([NIST SP 800-171 Rev. 2, requirement 3.1.1](https://doi.org/10.6028/NIST.SP.800-171r2)) CMMC Level 2 practice AC.L2-3.1.1. ## What 3.1.1 means in practice Every person, service and device that can reach the system has to be known in advance, and nothing else gets in. In practice that means an account inventory tied to named people, service accounts and managed identities with an owner, and a list of the devices allowed to connect. Accounts of people who have left are removed, and assessors test that by sampling recent departures. ## SPRS points and the CMMC POA&M - **CMMC Level 2 practice**: AC.L2-3.1.1 - **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. Sources: [NIST SP 800-171 DoD Assessment Methodology, version 1.2.1 (June 24, 2020), Annex A](https://www.acq.osd.mil/asda/dpc/cp/cyber/docs/safeguarding/NIST-SP-800-171-Assessment-Methodology-Version-1.2.1-6.24.2020.pdf); [32 CFR 170.21, Plan of Action and Milestones requirements](https://www.ecfr.gov/current/title-32/section-170.21). ## What an assessor checks for 3.1.1 NIST SP 800-171A gives 6 determination statements for 3.1.1, each found satisfied or other than satisfied. Determine if: - 3.1.1[a] authorized users are identified. - 3.1.1[b] processes acting on behalf of authorized users are identified. - 3.1.1[c] devices (and other systems) authorized to connect to the system are identified. - 3.1.1[d] system access is limited to authorized users. - 3.1.1[e] system access is limited to processes acting on behalf of authorized users. - 3.1.1[f] system access is limited to authorized devices (including other systems). [NIST SP 800-171A (June 2018), assessment objectives for 3.1.1](https://doi.org/10.6028/NIST.SP.800-171A) ## Evidence that shows 3.1.1 is met - A current list of active accounts with the person or owner behind each one, service accounts and managed identities included. - Access request and approval records for a sample of recently created accounts. - Records showing the accounts of people who left were disabled, matched against HR departure dates. - The list of devices and systems allowed to connect, such as a device management enrollment report. - Sign-in policy settings that turn away unknown users and devices. ## How PolicyCortex gathers the evidence PolicyCortex reads this evidence with the collectors below, read only, and grades 3.1.1 from it. Each line says what the product checks. - **Microsoft Entra ID: Conditional Access.** Checks that Conditional Access policies restrict sign-in to the system to authorized users. - **AWS: IAM.** Flags IAM user credentials that have not been used for 90 days. - **AWS: S3 buckets.** Checks that each S3 bucket blocks public access and is neither publicly readable nor publicly writable. - **AWS: EC2 and VPC networking.** Checks that running EC2 instances have no public IPv4 address, that subnets do not hand out public addresses, and that instances require IMDSv2. - **AWS: Data stores.** Checks that RDS instances and Redshift clusters are not publicly accessible. - **AWS: Load balancers, API Gateway, CloudFront and Lambda.** Checks that no Lambda function policy grants public access. ## Related pages - **Calculator**: [SPRS score calculator: mark 3.1.1 and the other 109 requirements and see the score.](https://policycortex.com/sprs-score-calculator#family-AC) - **Sample package**: [Sample package: an SSP, a POA&M and an evidence chain the product generated from demonstration data.](https://policycortex.com/sample-package) - **Family**: [All 22 Access Control requirements (3.1).](https://policycortex.com/nist-800-171/access-control) - **Next**: [3.1.2: Transaction Control](https://policycortex.com/nist-800-171/access-control/3.1.2) - **All requirements**: [All 110 NIST SP 800-171 requirements, by family.](https://policycortex.com/nist-800-171) Meet the requirement once. Keep the evidence current. [Request Access](https://app.policycortex.com/auth?mode=request-access) ยท [Book a call](https://policycortex.com/book) ## Register colophon | Seq | Label | SHA3-256 | Prev | |---|---|---|---| | REC 0000 | REQUIREMENT | 7d789bf1f2f1 | a15d850cfdf7 | | REC 0001 | MEANING | 67b046e8335f | 7d789bf1f2f1 | | REC 0002 | POINTS AND POA&M | 79a1cc43aae6 | 67b046e8335f | | REC 0003 | ASSESSMENT OBJECTIVES | af4c55f423e7 | 79a1cc43aae6 | | REC 0004 | EVIDENCE | fc2e8774cf76 | af4c55f423e7 | | REC 0005 | COLLECTORS | 807c1c478408 | fc2e8774cf76 | | REC 0006 | RELATED | c4b499183b78 | 807c1c478408 | Head sha3:c4b499183b78b39dd8eddf9f9621570919e568cb757780eff2bd5188d865f66d. Each digest is SHA3-256 over the previous digest, the register key, the record label, and the record copy; a second party can recompute it from this document.