3.5.3Require multi-factor authentication

MFA for admin accounts and for anything reached over the network.

IA
Level 2
3 or 5 pt
Rev. 3: Reworded

The requirement, verbatim

NIST SP 800-171 Rev. 2 · 3.5.3
Use multifactor authentication for local and network access to privileged accounts and for network access to non-privileged accounts.

Requirement 3.5.3, practice name in the CMMC assessment guide: Multifactor Authentication.

NIST's discussion

Multifactor authentication requires the use of two or more different factors to authenticate. The factors are defined as something you know (e.g., password, personal identification number [PIN]); something you have (e.g., cryptographic identification device, token); or something you are (e.g., biometric). Multifactor authentication solutions that feature physical authenticators include hardware authenticators providing time-based or challenge-response authenticators and smart cards. In addition to authenticating users at the system level (i.e., at logon), organizations may also employ authentication mechanisms at the application level, when necessary, to provide increased information security. Access to organizational systems is defined as local access or network access. Local access is any access to organizational systems by users (or processes acting on behalf of users) where such access is obtained by direct connections without the use of networks. Network access is access to systems by users (or processes acting on behalf of users) where such access is obtained through network connections (i.e., nonlocal accesses). Remote access is a type of network access that involves communication through external networks. The use of encrypted virtual private networks for connections between organization-controlled and non-organization controlled endpoints may be treated as internal networks with regard to protecting the confidentiality of information.

NIST SP 800-63-3 provides guidance on digital identities.

NIST SP 800-171 Rev. 2, discussion under 3.5.3. Whitespace normalised; wording unchanged.

Assessment objectives

An assessor decides each of these separately. The requirement is met only when every objective is.

[a] privileged accounts are identified
[b] multifactor authentication is implemented for local access to privileged accounts
[c] multifactor authentication is implemented for network access to privileged accounts
[d] multifactor authentication is implemented for network access to non-privileged accounts

NIST SP 800-171A, determination statements for 3.5.3.

For assessors: examine, interview, test

NIST SP 800-171A names what an assessor may examine, whom they may interview, and what they may test for this requirement. Assessors select from these lists; they are not a checklist of everything you must produce.

Examine

Identification and authentication policy
procedures addressing user identification and authentication
system security plan
system design documentation
system configuration settings and associated documentation
system audit logs and records
list of system accounts
other relevant documents or records

Interview

Personnel with authenticator management responsibilities
personnel with information security responsibilities
system or network administrators

Test

Mechanisms supporting or implementing authenticator management capability

NIST SP 800-171A, potential assessment methods and objects for 3.5.3.

Evidence

No evidence examples are published for this requirement yet. The objectives above are what an assessor checks; evidence is whatever shows each one is true in your environment, dated and kept with your system security plan.

Scoring weight

Worth 5 points, or 3 in one specific case. Not meeting this requirement subtracts 5 from your 110-point SPRS score; the partial-credit rule below can reduce that to 3.

Partial credit. 3 if MFA is implemented only for remote and privileged users; 5 if MFA is not implemented for any users.

DoD NIST SP 800-171 Assessment Methodology v1.2.1 weighting, as carried in the Bedrock scoring table. The score starts at 110 and subtracts the weight of every requirement not met.

In Rev. 3

Rev. 2 is what your contract requires today. A standing DoD class deviation keeps Rev. 2 in force; NIST has published Rev. 3, but it is not adopted for contracts. In Rev. 3 this requirement is reworded: 03.05.03 Multi-Factor Authentication.

See the Rev. 2 and Rev. 3 wording word by word, or start with the status page.

Where this page's facts come from

Requirement text: bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.basicRequirement@rev2
Discussion: bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.discussion@rev2
Practice name: bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.title@rev2 (CMMC Assessment Guide practice name)
Objectives: bedrock-cmmc-api@89b8e8e:migrations/005_reference_objectives.sql#AssessmentObjective.description@rev2
Examine, interview, test: bedrock-cmmc-api@89b8e8e:migrations/005_reference_objectives.sql#AssessmentObjective.description@rev2 ({examineGuidance, interviewGuidance, testGuidance})
Level: bedrock-cmmc-api@89b8e8e:migrations/021_fix_level1_requirements.sql#Requirement.cmmcLevel@rev2
Weight: bedrock-cmmc-api@89b8e8e:internal/cmmc/requirement_values.go#requirementValues (DoD AM v1.2.1 / eMASS L2 template v3.8)
Rev. 3 mapping: bedrock-cmmc-api@89b8e8e:docs/reference/nist-800-171-rev3/normalized/r2_r3_transition_map.json#r2_to_r3
Plain-language title and summary: editorial/CMMC Navigator.dc.html#RAW (Foxx Cyber editorial)