Overview
  1. 03.01: Access Control
  2. 03.02: Awareness and Training
  3. 03.03: Audit and Accountability
  4. 03.04: Configuration Management
  5. 03.05: Identification and Authentication
  6. 03.06: Incident Response
  7. 03.07: Maintenance
  8. 03.08: Media Protection
  9. 03.09: Personnel Security
  10. 03.10: Physical Protection
  11. 03.11: Risk Assessment
  12. 03.12: Security Assessment
  13. 03.13: System and Communications Protection
  14. 03.14: System and Information Integrity

Security Requirements for 03.05.03 Multifactor Authentication

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.[SP 800-63-3] provides guidance on digital identities.

Assessment GuidanceExamine 0/8

How an assessor determines this requirement is met. Source: CMMC Assessment Guide – Level 2, Version 2.13 (NIST SP 800-171 Rev. 2).

Discussion

Implement a combination of two or more factors of authentication to verify privileged account holders’ identity regardless of how the user is accessing the account. Implement a combination of two or more factors for non-privileged users accessing the system over a network.

The implementation of multi-factor authentication will depend on the environment and business needs. Although two-factor authentication directly on the computer is most common, there are situations (e.g., multi-factor identification for a mission system that cannot be altered) where additional technical or physical solutions can provide security. If a mobile device is used to access a system or application containing CUI, multi-factor authentication is required. This requirement, IA.L2-3.5.3, requires multifactor authentication for network access to non-privileged accounts and complements five other requirements dealing with remote access (AC.L2-3.1.12, AC.L2-3.1.14, AC.L2-3.1.13, AC.L2-3.1.15, and MA.L2-3.7.5:

AC.L2-3.1.12 requires the control of remote access sessions.

AC.L2-3.1.14 limits remote access to specific access control points.

AC.L2-3.1.13 requires the use of cryptographic mechanisms when enabling remote sessions.

AC.L2-3.1.15 requires authorization for privileged commands executed during a remote.

Finally, MA.L2-3.7.5 requires the addition of multifactor authentication for remote maintenance sessions.

This requirement, IA.L2-3.5.3, also enhances IA.L2-3.5.2, which is a requirement for a less rigorous form of user authentication.

Examples

  1. Example 1

    You decide to implement multifactor authentication (MFA) to improve security of your network. Your first step is enabling MFA on VPN access to your internal network [c, d]. When users initiate remote access, they will be prompted for the additional authentication factor.

  2. Example 2

    Because you also use a cloud-based email solution, you require MFA for access to that resource as well [c, d]. Finally, you enable MFA for both local and network logins for the system administrator accounts used to patch and manage servers [a, b, c].

Assessment Methods

Examine
The process of reviewing, inspecting, observing, studying, or analyzing assessment objects (e.g., policies, procedures, plans, system designs, mechanisms) to facilitate understanding, achieve clarification, or obtain evidence.Example: An assessor reads the access control policy and inspects system configuration settings to confirm they match.

Not all of the evidence listed is required to meet this requirement — check the items your organization has collected.

Interview
The process of holding discussions with individuals or groups within an organization to facilitate understanding, achieve clarification, or identify the location of evidence.Example: An assessor asks a system administrator to describe how user accounts are approved, reviewed, and disabled.
  • Personnel with authenticator management responsibilities
  • Personnel with information security responsibilities
  • System or network administrators
Test
The process of exercising assessment objects (e.g., activities, mechanisms) under specified conditions to compare actual behavior with expected behavior.Example: An assessor attempts to sign in with a disabled account to confirm that access is denied.
  • Mechanisms supporting or implementing authenticator management capability

Potential Assessment Considerations

  • Does the system uniquely identify and authenticate users, including privileged accounts [b, c, d]?

Key References

NIST SP 800-171 Rev. 2 3.5.3

Evidence

  1. 03.05.03.a

    Privileged accounts are identified

  1. 03.05.03.b

    Multifactor authentication is implemented for local access to privileged accounts

  1. 03.05.03.c

    Multifactor authentication is implemented for network access to privileged accounts

  1. 03.05.03.d

    Multifactor authentication is implemented for network access to non-privileged accounts