User Identification And Authentication

---
name: "User Identification and Authentication (03.05.01)_user-identification-and-authentication"
description: "Uniquely identify and authenticate system users, and associate that unique identification with processes acting on behalf of those users."
category: "authentication"
version: "3.0"
author: "cyberstrike-official"
tags:
  - nist
  - sp800-171
  - rev3
  - user identification and authentication (03-05-01)
  - family-03.05
  - cui-protection
  - cmmc
tech_stack:
  - aws
  - azure
  - active-directory
  - linux
  - windows
cwe_ids:
  - CWE-287
chains_with: []
prerequisites: []
severity_boost: {}
---

# User Identification and Authentication (03.05.01) User Identification and Authentication

## High-Level Description

**Family:** Identification and Authentication
**Framework:** NIST SP 800-171 Rev 3
**Applicability:** Systems processing, storing, or transmitting CUI

Uniquely identify and authenticate system users, and associate that unique identification with processes acting on behalf of those users.
Re-authenticate users when [organization-defined] .

## What to Check

- [ ] Verify User Identification and Authentication (03.05.01) User Identification and Authentication is implemented for CUI systems
- [ ] Review SSP documentation for User Identification and Authentication (03.05.01)
- [ ] Validate CMMC Level 2 assessment objective for User Identification and Authentication (03.05.01)
- [ ] Confirm POA&M addresses any gaps for User Identification and Authentication (03.05.01)

## How to Test

### Step 1: Review System Security Plan

Examine the SSP for User Identification and Authentication (03.05.01) implementation description and responsible parties.

### Step 2: Assess Implementation

```
# Verify security controls protecting CUI
# Check access controls, encryption, monitoring as applicable

# For Linux systems:
ls -la /etc/security/ 2>/dev/null
grep -r "CUI\|controlled" /etc/security/ 2>/dev/null

# For cloud:
# Use cloud-audit-mcp tools to assess posture
```

### Step 3: CMMC Assessment Validation

Verify this requirement passes CMMC Level 2 assessment methodology per SP 800-171A Rev 3.

## Tools

| Tool            | Purpose                      | Usage                  |
| --------------- | ---------------------------- | ---------------------- |
| cloud-audit-mcp | Assess cloud CUI environment | `cloud_audit_*` tools  |
| Manual Review   | SSP and POA&M review         | Documentation analysis |

## Remediation Guide

### Requirement Statement

Uniquely identify and authenticate system users, and associate that unique identification with processes acting on behalf of those users.
Re-authenticate users when [organization-defined] .

### Supplemental Guidance

System users include individuals (or system processes acting on behalf of individuals) who are authorized to access a system. Typically, individual identifiers are the usernames associated with the system accounts assigned to those individuals. Since system processes execute on behalf of groups and roles, organizations may require the unique identification of individuals in group accounts or the accountability of individual activity. The unique identification and authentication of users apply to all system accesses. Organizations use passwords, physical authenticators, biometrics, or some combination thereof to authenticate user identities. Organizations may re-authenticate individuals in certain situations, including when roles, authenticators, or credentials change; when the execution of privileged functions occurs; after a fixed time period; or periodically.

## Risk Assessment

| Finding                                                                                                  | Severity | Impact                                             |
| -------------------------------------------------------------------------------------------------------- | -------- | -------------------------------------------------- |
| User Identification and Authentication (03.05.01) User Identification and Authentication not implemented | High     | CUI Protection - Identification and Authentication |
| User Identification and Authentication (03.05.01) partially implemented (POA&M)                          | Medium   | CMMC certification risk                            |

## CWE Categories

| CWE ID  | Title                   |
| ------- | ----------------------- |
| CWE-287 | Improper Authentication |

## References

- [NIST SP 800-171 Rev 3](https://csrc.nist.gov/pubs/sp/800/171/r3/final)
- [NIST SP 800-171A Rev 3 (Assessment)](https://csrc.nist.gov/pubs/sp/800/171/a/r3/final)
- [CMMC Model Overview](https://www.acq.osd.mil/cmmc/)
- [NIST OSCAL Content](https://github.com/usnistgov/oscal-content)

## Checklist

- [ ] SSP documents User Identification and Authentication (03.05.01) implementation
- [ ] Evidence of operating effectiveness collected
- [ ] POA&M addresses any gaps
- [ ] CMMC assessment objective met
- [ ] Continuous monitoring active