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NIST 800-171 & CMMC 2.0 - Cloud Control Mapping

Scope

Covers NIST SP 800-171 security requirements for Controlled Unclassified Information (CUI) and CMMC 2.0 certification levels, including CUI enclave design patterns, control family mappings, and cloud provider FedRAMP/IL status. Does not cover FedRAMP authorization process details (see compliance/fedramp.md) or general identity architecture (see general/identity.md).

Overview

NIST SP 800-171 defines security requirements for protecting Controlled Unclassified Information (CUI) in non-federal systems. It is the foundation for the Cybersecurity Maturity Model Certification (CMMC 2.0), which the Department of Defense uses to assess contractor cybersecurity posture.

NIST 800-171 Revision 3 (May 2024) restructured the control families and updated requirements to align more closely with NIST SP 800-53 Rev. 5. Rev. 3 reorganizes the 110 controls from Rev. 2 into a different structure with updated control text and new organization-defined parameters (ODPs). The DoD has confirmed that CMMC 2.0 Level 2 assessments will continue to reference Rev. 2 until a future rulemaking formally adopts Rev. 3. Organizations should begin gap analysis against Rev. 3 now but maintain compliance with Rev. 2 for current CMMC assessments.

CMMC 2.0 Levels: - Level 1 (Foundational): 17 practices — basic cyber hygiene (self-assessment) - Level 2 (Advanced): 110 practices — aligned 1:1 with NIST 800-171 Rev. 2 (third-party assessment for critical contracts) - Level 3 (Expert): 110+ practices — NIST 800-171 plus subset of NIST 800-172 (government-led assessment)

CMMC Phase 2 Timeline: CMMC Phase 1 (began 2025) requires Level 1 and Level 2 self-assessments in applicable contracts. Phase 2 is scheduled for November 2026, when Level 2 third-party (C3PAO) assessments become a requirement in applicable DoD contracts. Organizations expecting to bid on contracts requiring Level 2 certification should begin C3PAO assessment preparation well in advance of the November 2026 deadline.

Applicability: Required for any organization handling CUI under DoD contracts. Increasingly adopted by other federal agencies and as a general cybersecurity framework.

Cloud Provider Status: | Provider | FedRAMP | IL (Impact Level) | CUI Environment | |----------|---------|-------------------|-----------------| | AWS | High (GovCloud), Moderate (commercial) | IL2, IL4, IL5 (GovCloud), IL6 (Secret region) | AWS GovCloud | | Azure | High (Government), Moderate (commercial) | IL2, IL4, IL5 (Government), IL6 (Secret) | Azure Government | | GCP | High (Assured Workloads), Moderate (commercial) | IL2, IL4, IL5 (Assured Workloads) | GCP Assured Workloads |


Checklist

  • [Critical] Is CUI identified and categorized across all systems? (know what you are protecting and where it resides)
  • [Critical] Is the CUI boundary (enclave) defined and documented? (system security plan, network diagrams)
  • [Critical] Is the cloud environment deployed in a FedRAMP-authorized region? (GovCloud, Azure Government, or Assured Workloads for IL4+)
  • [Critical] Is multi-factor authentication enforced for all users accessing CUI? (FIPS 140-2 validated MFA)
  • [Critical] Are audit logs comprehensive and tamper-evident? (who accessed what CUI, when, from where)
  • [Critical] Is encryption FIPS 140-2 validated for data at rest and in transit? (not just enabled — validated modules)
  • [Critical] Is a System Security Plan (SSP) documented? (maps each of the 110 controls to implementation)
  • [Recommended] Is a Plan of Action and Milestones (POA&M) maintained? (for controls not yet fully implemented)
  • [Critical] Are incident response procedures defined and tested? (72-hour DoD reporting requirement)
  • [Recommended] Is media sanitization handled per NIST 800-88? (before reuse or disposal of storage)
  • [Critical] Is access control based on least privilege with separation of duties? (role-based, regularly reviewed)
  • [Recommended] Are personnel security requirements met? (background checks, CUI handling training)
  • [Critical] Is there a continuous monitoring program? (ongoing assessment, not point-in-time)

Why This Matters

CMMC is a contract requirement, not optional. Without the required CMMC level, organizations cannot bid on or continue DoD contracts. Non-compliance can result in loss of contracts, False Claims Act liability, and reputational damage.

The 2024 CMMC final rule made third-party assessments mandatory for Level 2 on contracts involving critical CUI. Self-assessment is no longer sufficient for many contractors. Cloud architects must design CUI enclaves that are assessable and defensible.


NIST 800-171 Control Families (14 Families, 110 Controls)

1. Access Control (AC) — 22 Controls

Purpose: Limit system access to authorized users and transactions.

Key Controls Description Cloud Implementation
AC 3.1.1 Limit system access to authorized users IAM policies, RBAC, identity federation (AWS IAM, Entra ID (formerly Azure AD), GCP IAM)
AC 3.1.2 Limit access to authorized transactions/functions Least privilege policies, service control policies, conditional access
AC 3.1.3 Control CUI flow per authorizations VPC flow controls, network segmentation, DLP policies
AC 3.1.5 Employ least privilege Scoped IAM roles, no wildcard permissions, regular access reviews
AC 3.1.7 Prevent non-privileged users from executing privileged functions Separate admin roles, PIM/PAM (Azure PIM, AWS SSO with elevated roles)
AC 3.1.8 Limit unsuccessful logon attempts Account lockout policies, failed login monitoring, CloudTrail/Sign-in logs
AC 3.1.12 Monitor and control remote access sessions VPN with MFA, bastion hosts, session recording (AWS SSM, Azure Bastion)
AC 3.1.22 Control CUI posted to publicly accessible systems S3 Block Public Access, Azure Storage firewall, prevent public exposure

2. Awareness and Training (AT) — 3 Controls

Purpose: Ensure personnel are aware of security risks and trained in their responsibilities.

Key Controls Description Cloud Implementation
AT 3.2.1 Ensure awareness of security risks Security awareness training program, phishing simulations
AT 3.2.2 Ensure training for roles with security responsibilities Cloud-specific training (AWS/Azure/GCP security certifications)
AT 3.2.3 Provide insider threat awareness training Insider threat program, monitoring privileged user activity

3. Audit and Accountability (AU) — 9 Controls

Purpose: Create, protect, and retain audit records.

Key Controls Description Cloud Implementation
AU 3.3.1 Create and retain audit records CloudTrail, Azure Activity Log, GCP Audit Logs — all API calls logged
AU 3.3.2 Ensure individual accountability via audit User-level logging (no shared accounts), correlation of identity to action
AU 3.3.4 Alert on audit process failure Monitoring for logging pipeline failures, CloudWatch alarms
AU 3.3.5 Correlate audit review and reporting SIEM integration (Splunk, Sentinel, Chronicle), centralized log analysis
AU 3.3.8 Protect audit information from unauthorized access Immutable log storage (S3 Object Lock, WORM storage), separate log account
AU 3.3.9 Limit audit log management to authorized individuals Separate security account, restricted IAM for log deletion

4. Configuration Management (CM) — 9 Controls

Purpose: Establish and maintain baseline configurations and inventories.

Key Controls Description Cloud Implementation
CM 3.4.1 Establish and maintain baseline configurations AMI/image baselines, IaC (Terraform/CloudFormation), AWS Config
CM 3.4.2 Establish security configuration settings CIS Benchmarks, AWS Config Rules, Azure Policy, hardened images
CM 3.4.5 Define and enforce access restrictions for change CI/CD approval gates, branch protection, change management process
CM 3.4.6 Employ least functionality Disable unnecessary services/ports, minimal container images, remove unused packages
CM 3.4.8 Apply deny-by-exception (blacklisting) Security groups default deny, NACLs, application whitelisting

5. Identification and Authentication (IA) — 11 Controls

Purpose: Identify and authenticate users, processes, and devices.

Key Controls Description Cloud Implementation
IA 3.5.1 Identify system users, processes, devices Unique user accounts, service accounts, device certificates
IA 3.5.2 Authenticate identities before access SSO with MFA (Okta, Entra ID, AWS SSO), SAML/OIDC federation
IA 3.5.3 Use MFA for privileged and network access FIPS 140-2 validated MFA (hardware tokens, FIDO2, PIV/CAC)
IA 3.5.7 Enforce minimum password complexity Password policies, prefer passwordless (FIDO2), minimum 12 characters
IA 3.5.10 Store and transmit only cryptographically protected passwords Secrets Manager, no plaintext credentials, bcrypt/scrypt hashing

6. Incident Response (IR) — 3 Controls

Purpose: Establish incident handling capability.

Key Controls Description Cloud Implementation
IR 3.6.1 Establish incident handling capability IR plan, GuardDuty/Defender/SCC for detection, automated response playbooks
IR 3.6.2 Track, document, and report incidents Incident tracking system, DFARS 252.204-7012 72-hour reporting to DIBNet
IR 3.6.3 Test incident response capability Tabletop exercises, simulation drills, automated IR playbook testing

7. Maintenance (MA) — 6 Controls

Purpose: Perform maintenance on organizational systems.

Key Controls Description Cloud Implementation
MA 3.7.1 Perform maintenance on systems Patch management (SSM Patch Manager, Azure Update Management), maintenance windows
MA 3.7.2 Control maintenance tools Approved bastion access, recorded sessions, no unauthorized remote tools
MA 3.7.5 Require MFA for remote maintenance MFA-gated bastion/SSM access, PIV/CAC for privileged sessions

8. Media Protection (MP) — 9 Controls

Purpose: Protect CUI on digital and physical media.

Key Controls Description Cloud Implementation
MP 3.8.1 Protect CUI on system media Encryption at rest (KMS, Azure Key Vault, Cloud KMS), FIPS 140-2 validated
MP 3.8.3 Sanitize media before disposal/reuse EBS/disk encryption with key deletion, NIST 800-88 procedures
MP 3.8.6 Implement cryptographic mechanisms for CUI during transport TLS 1.2+ (FIPS endpoints), encrypted VPN tunnels, private connectivity

9. Personnel Security (PS) — 2 Controls

Purpose: Screen individuals and protect CUI upon personnel actions.

10. Physical Protection (PE) — 6 Controls

Purpose: Limit physical access to systems (largely inherited from cloud provider in FedRAMP).

11. Risk Assessment (RA) — 3 Controls

Purpose: Assess risk to operations, assets, and individuals.

Key Controls Description Cloud Implementation
RA 3.11.1 Periodically assess risk Regular vulnerability scanning (Inspector, Qualys), penetration testing
RA 3.11.2 Scan for vulnerabilities periodically and on new threats Automated scanning (Inspector, Defender for Cloud, SCC), CVE monitoring
RA 3.11.3 Remediate vulnerabilities per risk assessments Patching SLAs, vulnerability management program, risk-based prioritization

12. Security Assessment (CA) — 4 Controls

Purpose: Assess, monitor, and correct deficiencies.

Key Controls Description Cloud Implementation
CA 3.12.1 Periodically assess security controls Annual assessment, continuous monitoring (AWS Config, Defender, SCC)
CA 3.12.2 Develop and implement POA&Ms Track unimplemented controls, remediation timeline, milestone tracking
CA 3.12.3 Monitor security controls continuously Security Hub, Defender for Cloud, SCC dashboards, automated compliance checks
CA 3.12.4 Develop and update SSP System Security Plan covering all 110 controls, updated with changes

13. System and Communications Protection (SC) — 16 Controls

Purpose: Monitor, control, and protect communications.

Key Controls Description Cloud Implementation
SC 3.13.1 Monitor and protect communications at system boundaries WAF, network firewalls, VPC boundaries, TLS termination
SC 3.13.4 Prevent unauthorized transfer of information DLP policies (Macie, Purview, DLP), egress filtering, VPC endpoints
SC 3.13.8 Implement cryptographic mechanisms for CUI in transit FIPS 140-2 TLS endpoints, VPN encryption, private connectivity
SC 3.13.11 Employ FIPS-validated cryptography FIPS endpoints for AWS/Azure/GCP, FIPS-validated key management
SC 3.13.16 Protect CUI confidentiality at rest AES-256 encryption, KMS-managed keys, FIPS 140-2 Level 2+ HSMs

14. System and Information Integrity (SI) — 7 Controls

Purpose: Identify, report, and correct system flaws.

Key Controls Description Cloud Implementation
SI 3.14.1 Identify and correct system flaws in a timely manner Patch management, automated remediation, CVE tracking
SI 3.14.2 Provide protection from malicious code Endpoint protection, container scanning, malware detection (GuardDuty)
SI 3.14.6 Monitor systems for unauthorized access SIEM, IDS/IPS, anomaly detection, GuardDuty/Defender/SCC
SI 3.14.7 Identify unauthorized use of systems User behavior analytics, impossible travel detection, anomaly alerts

CUI Enclave Patterns

AWS GovCloud CUI Enclave

AWS GovCloud (US)
┌─────────────────────────────────────────────┐
│  AWS Organizations + SCPs                    │
│  ┌────────────────────────────────────────┐  │
│  │  CUI VPC                               │  │
│  │  ├── Private subnets only              │  │
│  │  ├── VPC endpoints for AWS services    │  │
│  │  ├── No internet gateway               │  │
│  │  ├── Flow logs → S3 (WORM)            │  │
│  │  │                                     │  │
│  │  │  Compute: EC2/ECS/EKS              │  │
│  │  │  (FIPS endpoints, hardened AMIs)    │  │
│  │  │                                     │  │
│  │  │  Data: RDS/S3/DynamoDB             │  │
│  │  │  (KMS CMK, FIPS 140-2 validated)   │  │
│  │  │                                     │  │
│  │  │  Identity: AWS SSO + MFA           │  │
│  │  │  (PIV/CAC via SAML federation)     │  │
│  │  └────────────────────────────────────┘  │
│  │                                           │
│  │  Logging Account (separate, restricted)   │
│  │  ├── CloudTrail (org-wide, S3 Object Lock)│
│  │  ├── VPC Flow Logs                        │
│  │  └── GuardDuty findings                   │
│  └───────────────────────────────────────────┘
└─────────────────────────────────────────────┘

Key Enclave Design Principles

  1. Use FedRAMP High authorized services only — Not all cloud services are authorized
  2. FIPS endpoints everywhere*.fips.us-gov-west-1.amazonaws.com
  3. No public internet access — VPC endpoints for AWS services, no IGW
  4. Encrypt everything with CMKs — Customer-managed keys in CloudHSM (FIPS 140-2 Level 3) or KMS (Level 2)
  5. Immutable audit logs — S3 Object Lock in Governance or Compliance mode
  6. Separate accounts for logging, security tooling, and workloads
  7. Continuous compliance monitoring — AWS Config + Security Hub with NIST 800-171 standards

Azure Government CUI Enclave

  • Deploy in Azure Government regions (US Gov Virginia, US Gov Arizona)
  • Use Azure Policy with NIST 800-171 built-in initiative
  • Azure Defender for Cloud with regulatory compliance dashboard
  • Azure Key Vault with HSM backing (FIPS 140-2 Level 2/3)
  • Entra ID with Conditional Access + FIDO2/PIV MFA

GCP Assured Workloads CUI Enclave

  • Create Assured Workloads folder with IL4/IL5 compliance regime
  • Restricts services to FedRAMP High authorized only
  • Enforces data residency (US-only regions)
  • CMEK with Cloud HSM (FIPS 140-2 Level 3)
  • VPC Service Controls for data exfiltration prevention

Common Decisions (ADR Triggers)

  • CUI boundary definition — what systems are in scope, where CUI flows
  • Cloud region selection — GovCloud vs commercial with FedRAMP, IL level requirements
  • MFA technology — PIV/CAC vs FIDO2 vs software MFA (FIPS 140-2 validation required)
  • Encryption key management — KMS managed vs CloudHSM (Level 2 vs Level 3)
  • Logging architecture — centralized logging account, retention period (3+ years recommended)
  • CMMC assessment scope — which systems, Level 1 vs Level 2 vs Level 3
  • SSP and POA&M ownership — who maintains, review cadence, assessment preparation

See Also

  • compliance/fedramp.md — FedRAMP authorization process and controls
  • general/security.md — General security controls
  • general/identity.md — IAM and authentication architecture
  • general/governance.md — Cloud governance and policy-as-code
  • general/stig-hardening.md — STIG compliance, SCAP scanning, and security hardening