CMMC Level 2 Practice 3.3.8: Protect audit information and audit logging tools from unauthorized access, modification, and

CMMC Level 2 Practice 3.3.8 requires you to prevent unauthorized users (and unauthorized admins) from accessing, altering, deleting, or disabling audit logs and the tools that generate and store them. Operationalize it by locking down log access with least privilege and MFA, hardening and separating logging infrastructure, and proving integrity through write-once/immutable storage, monitored configuration changes, and repeatable evidence capture (NIST SP 800-171 Rev. 2; DoD CMMC Program Guidance; 32 CFR Part 170).

Key takeaways:

• Treat audit logs and logging platforms as high-value assets; restrict access, changes, and deletion paths (NIST SP 800-171 Rev. 2).
• Protect “the pipeline” end-to-end: endpoints generating logs, collectors/agents, transport, SIEM, and archive targets.
• Evidence wins assessments: document the control, show configurations, and retain recurring proof of operation (DoD CMMC Program Guidance).

Audit records are only useful if you can trust them. CMMC Level 2 Practice 3.3.8 (mapped to NIST SP 800-171 Rev. 2) focuses on preserving that trust by protecting both the audit information (the logs) and the audit logging tools (the systems and services that create, collect, store, and analyze logs) from unauthorized access and tampering (NIST SP 800-171 Rev. 2; DoD CMMC Program Guidance; 32 CFR Part 170).

For a Compliance Officer, CCO, or GRC lead, the fastest path to “operational” is to define the scope around your CUI environment, decide who can read logs versus who can administer logging, and then implement technical controls that make unauthorized modification and deletion hard and detectable. This is less about buying a SIEM and more about controlling privileges, protecting the log data lifecycle, and having clean, repeatable evidence that your protections are in place and functioning.

Assessment teams typically look for two things: (1) technical settings that prevent or tightly constrain log access and alteration, and (2) proof you run the control continuously, not as a one-time configuration exercise (DoD CMMC Program Guidance).

Requirement: cmmc level 2 practice 3.3.8: protect audit information and audit logging tools from unauthorized access, modification, and requirement

Plain-English interpretation

You must secure:

1. Audit information: security logs, system logs, application logs, cloud audit trails, authentication logs, and any log archives related to your CUI environment.
2. Audit logging tools: agents, collectors, forwarders, log servers, SIEM platforms, cloud logging services, and any admin consoles or APIs that manage logging.

“Protect” means unauthorized people cannot view, change, delete, disable, or reconfigure logs and logging systems without detection and authorization. The minimum bar is strict access control and change control; mature implementations add immutability and alerting on logging control-plane changes (NIST SP 800-171 Rev. 2).

Regulatory text

Source excerpt: “CMMC Level 2 practice mapped to NIST SP 800-171 Rev. 2 requirement 3.3.8 (Protect audit information and audit logging tools from unauthorized access, modification, and).” (NIST SP 800-171 Rev. 2; DoD CMMC Program Guidance; 32 CFR Part 170)

Operator meaning: You need to (a) identify where audit logs and logging tools live in your environment, (b) restrict who can access and administer them, (c) prevent or tightly control modification/deletion, and (d) maintain evidence that these protections are configured and operating (NIST SP 800-171 Rev. 2; DoD CMMC Program Guidance).

Who it applies to (entity and operational context)

In-scope entities

• Defense contractors and subcontractors that handle Controlled Unclassified Information (CUI) and are pursuing/required to meet CMMC Level 2 (32 CFR Part 170; DoD CMMC Program Guidance).

In-scope operational contexts (typical)

• On-prem AD/Windows/Linux environments that store or process CUI.
• Cloud tenants/accounts (IaaS/PaaS/SaaS) used for CUI workflows, where audit trails exist at the provider control plane and the application layer.
• Managed services or third parties that operate logging/SIEM on your behalf; their administrative access becomes part of your scope because it can alter evidence (DoD CMMC Program Guidance).

What you actually need to do (step-by-step)

Step 1: Inventory audit log sources and logging tooling (define the “log chain”)

Create a map that covers:

• Sources: endpoints, servers, network devices, identity providers, cloud audit trails, key business apps touching CUI.
• Collection/transport: agents, forwarders, syslog relays, API collectors.
• Storage and analysis: SIEM, log analytics workspace, object storage/archive, backup targets.
• Administration points: consoles, APIs, service accounts, break-glass accounts.

Deliverable: a “logging architecture diagram + asset inventory” tied to your CUI boundary (NIST SP 800-171 Rev. 2).

Step 2: Define roles and least privilege for logs (read vs administer)

Separate duties explicitly:

• Log Readers (Security/IR): can query and export logs as needed.
• Log Administrators (Platform): can manage parsers, connectors, retention, and storage.
• System Admins (IT): should not automatically inherit rights to modify SIEM retention, delete indexes, or disable forwarding.

Implement:

• RBAC groups for log access.
• MFA for privileged access to logging platforms and log storage admin consoles.
• Time-bound or approved elevation for rare admin tasks.

Step 3: Protect against unauthorized modification and deletion

Pick controls appropriate to your tooling, then document the design choice.

Common patterns:

• Immutable/WORM storage for log archives (object lock, write-once retention, or equivalent).
• Retention controls that prevent ad-hoc deletion (only a small admin group can change retention).
• Restricted delete permissions at the storage layer (deny delete except via controlled workflow).
• Centralized logging so individual endpoints cannot “hide” by deleting local logs.

You’re aiming for a situation where an attacker who compromises a workstation cannot erase enterprise audit history without also compromising tightly controlled logging infrastructure.

Step 4: Harden and monitor the logging tools themselves

Treat the SIEM/log platform as a protected system:

• Patch and harden OS/services (if self-hosted).
• Restrict inbound admin access (private network, jump host, conditional access).
• Monitor configuration changes: alert on changes to collectors, retention, log source disablement, alerting rules, and admin role assignments.
• Protect service accounts and API keys used to collect logs; rotate credentials and scope permissions.

Step 5: Put change control around logging configuration

Document what requires approval:

• Disabling a log source
• Changing retention
• Adding a new admin
• Modifying forwarding rules
• Turning off audit features in key systems

Minimum operational practice:

• Ticket or approval record for changes.
• Evidence of review for high-risk changes (security sign-off for “reduce retention” or “disable logging”).

Step 6: Prove operation with recurring evidence capture (assessment readiness)

Assessors ask, “How do you know it’s still protected?” Build a lightweight, recurring evidence routine:

• Export RBAC/role membership for the logging platform.
• Screenshot or configuration export for retention/immutability settings.
• Sample alerts for logging disablement or privileged changes.
• Access logs showing admin actions on the logging platform.

Daydream (as a GRC workflow system) fits here as the place to map 3.3.8 to your control narrative, store the architecture diagram, and schedule recurring evidence capture so you do not scramble before assessment (DoD CMMC Program Guidance).

Required evidence and artifacts to retain

Keep artifacts that tie policy to configuration to proof:

Control design artifacts

• Logging architecture diagram and log flow inventory (sources → collector → SIEM → archive).
• Role matrix defining who can read logs vs administer logging tools.
• Configuration standards for logging platforms (MFA, RBAC, retention, immutability targets).

Control operation artifacts (high-value in exams)

• Current RBAC/group membership exports for SIEM/log storage.
• MFA/conditional access policy evidence for admin access to logging tools.
• Retention policy screenshots or config exports.
• Storage policy evidence showing delete protections/immutability settings (as supported by your platform).
• Change tickets/approvals for logging configuration changes.
• Samples of alerts/events showing detection of logging disablement or admin changes.

Common exam/audit questions and hangups

What assessors often ask

• “Who can delete logs? Show me the permission path.”
• “Can a domain admin modify SIEM retention or disable collection?”
• “Where are logs stored, and how do you prevent tampering after collection?”
• “Show me proof that audit logging tools are protected, not just the endpoints.”
• “How do you detect if logging stops for a critical system?”

Typical hangups

• Over-privileged administrators: broad admin roles that implicitly allow log deletion.
• SaaS/cloud gaps: teams collect endpoint logs but ignore cloud control-plane audit logs for identity and infrastructure.
• Evidence gaps: controls exist, but nobody captured screenshots/exports or can show role membership and retention settings on demand (DoD CMMC Program Guidance).

Frequent implementation mistakes (and how to avoid them)

1. Treating logs as “standard data.”
   Fix: classify audit logs as sensitive security records; apply stricter access controls than normal operational telemetry.

2. No separation between IT admin and audit admin.
   Fix: distinct roles for managing production systems vs managing the logging evidence systems; document and enforce with RBAC.

3. Local-only logging for critical assets.
   Fix: forward logs off-host quickly; keep central copies where endpoint compromise cannot erase history.

4. Retention set, but deletion still possible.
   Fix: verify delete permissions at each layer (SIEM UI, storage bucket, backup target). “Retention policy” is not the same as “cannot delete.”

5. One-time setup, no operational checks.
   Fix: recurring evidence capture and periodic access review for logging admins and readers (DoD CMMC Program Guidance).

Enforcement context and risk implications

No public enforcement cases were provided in the supplied source catalog, so you should treat this as an assessment-driven requirement under the CMMC program and NIST SP 800-171 mapping (32 CFR Part 170; DoD CMMC Program Guidance; NIST SP 800-171 Rev. 2). The practical risk is straightforward: if an incident occurs and logs are missing or untrustworthy, you lose investigative integrity and may be unable to demonstrate compliance performance during an assessment.

Practical execution plan (30/60/90)

First 30 days (stabilize scope and access)

• Define the CUI boundary and enumerate all log sources and logging tools in scope.
• Lock down admin access paths: MFA for SIEM/log admin consoles; remove shared accounts where possible.
• Produce the role matrix and identify who currently has log delete/retention-change permissions.

Days 31–60 (reduce tampering paths and formalize change control)

• Implement or tighten immutability/delete protections for log archives where your platform supports it.
• Turn on alerting for logging stoppage and for privileged changes (role changes, retention changes, connector disablement).
• Put ticketing approval in place for high-risk logging configuration changes; train admins on the workflow.

Days 61–90 (evidence automation and assessment readiness)

• Establish a recurring evidence capture routine (role exports, retention settings, sample alerts, change tickets).
• Run a tabletop test: simulate an “attacker tries to delete logs” scenario and confirm you can detect and demonstrate protections.
• Map the final control narrative and evidence checklist in Daydream so 3.3.8 stays current between assessments (DoD CMMC Program Guidance).

Frequently Asked Questions

Do we need a SIEM to meet CMMC Level 2 Practice 3.3.8?

The requirement is about protecting audit information and logging tools, not buying a specific product (NIST SP 800-171 Rev. 2). A SIEM often helps centralize and protect logs, but you can meet the requirement with other architectures if access, modification, and deletion are controlled.

Are cloud audit logs (like identity and control-plane logs) in scope?

If the cloud tenant is part of your CUI environment, its audit trails are part of “audit information” you need to protect (NIST SP 800-171 Rev. 2). You should restrict access to those logs and monitor administrative changes to logging settings.

How do we show “protected from modification” during an assessment?

Show the permission model (who can change or delete), the retention/immutability settings, and proof that configuration changes are monitored and approved (NIST SP 800-171 Rev. 2; DoD CMMC Program Guidance). Screenshots and configuration exports matter, but so do role membership exports and change tickets.

Can system administrators also be log administrators?

It can be allowed, but it increases risk and raises assessor questions. If you cannot separate roles, implement compensating controls: tighter approvals for retention/deletion changes, stronger monitoring of admin actions, and documented justification tied to least privilege (NIST SP 800-171 Rev. 2).

What logs count as “audit information” for 3.3.8?

Any records used to detect, investigate, or reconstruct events in the CUI environment count, including authentication logs, privilege changes, system events, and security tool logs (NIST SP 800-171 Rev. 2). Include logs from the logging platform itself (admin actions, configuration changes).

What’s the fastest way to avoid the “missing evidence” finding?

Write a short control narrative mapped to 3.3.8, then schedule recurring evidence capture for RBAC membership, retention/immutability settings, and logging change approvals (DoD CMMC Program Guidance). Store it centrally (for example, in Daydream) so the evidence is ready without a pre-assessment scramble.