NIST 800-171 3.3.8 (AU.L2-3.3.8): Audit Protection

Protect audit information and audit logging tools from unauthorized access, modification, and deletion.

NIST SP 800-171 Rev. 2, requirement 3.3.8

CMMC Level 2 practice AU.L2-3.3.8Published 2026-11-11

What 3.3.8 means in practice

Audit logs are only useful if nobody can quietly read, alter or delete them. Restrict access to the log data and the logging tools, protect stored logs against change, for example with retention locks or integrity validation, and keep administrators away from the logs of their own actions.

SPRS points and the CMMC POA&M

CMMC Level 2 practice: AU.L2-3.3.8
SPRS points: 1 point. When it is not met, the DoD Assessment Methodology subtracts 1 from the score of 110.
CMMC POA&M: Allowed. It is worth 1 point, and 32 CFR 170.21(a)(2)(ii) admits requirements worth 1 point. Conditional status also needs a score of at least 88, and the item must be closed within 180 days.

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 3.3.8

NIST SP 800-171A gives 6 determination statements for 3.3.8, each found satisfied or other than satisfied. Determine if:

3.3.8[a] audit information is protected from unauthorized access.
3.3.8[b] audit information is protected from unauthorized modification.
3.3.8[c] audit information is protected from unauthorized deletion.
3.3.8[d] audit logging tools are protected from unauthorized access.
3.3.8[e] audit logging tools are protected from unauthorized modification.
3.3.8[f] audit logging tools are protected from unauthorized deletion.

NIST SP 800-171A (June 2018), assessment objectives for 3.3.8

Evidence that shows 3.3.8 is met

Access permissions on log storage and on the logging tools.
Settings that prevent modification or deletion, such as retention locks or log file integrity validation.
Logs of access to the audit data itself.

How PolicyCortex gathers the evidence

PolicyCortex reads this evidence with the collectors below, read only, and grades 3.3.8 from it. Each line says what the product checks.

Azure: Role assignments. Checks that Azure role assignments restrict access to Log Analytics workspaces and audit data.
Azure Monitor: Log Analytics workspaces. Checks workspace settings that protect audit logs from modification and keep them for at least 90 days.
AWS: CloudTrail and CloudWatch. Checks that CloudTrail log file validation is on and that the logs are encrypted with a KMS key.

Related pages

Calculator: SPRS score calculator: mark 3.3.8 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 9 Audit and Accountability requirements (3.3).
Previous: 3.3.7: Authoritative Time
Next: 3.3.9: Audit Management
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.