IA.L2-3.5.3 Multifactor Authentication

CMMC Requirement IA.L2-3.5.3 – Multifactor Authentication: Use multifactor authentication for local and network access to privileged accounts and for network access to non-privileged accounts.

Links to Publicly Available Resources

• Amazon Web Services – Operational Best Practices for CMMC 2.0 Level 2
  The following provides a sample mapping between the Cybersecurity Maturity Model Certification (CMMC) 2.0 Level 2 and AWS managed Config rules. Each Config rule applies to a specific AWS resource, and relates to one or more CMMC 2.0 Level 2 controls. A CMMC 2.0 Level 2 control can be related to multiple Config rules.

• BrightTALK – Cybersecurity Roundtable: MFA Bypass and How to Defend Against It
  This video consists of a panel of cybersecurity experts discussing advanced MFA bypass techniques and examining how their clients have enhanced their cybersecurity posture to respond.

• BrightTALK – FIDO Deployment Challenges & Best Practices for FIDO Key Management
  Webinar presented by Thales and Verasec on challenges and best practices for deploying and managing FIDO (phishing-resistant MFA).

• CMMC Level 2 Assessment Guide
  This document provides assessment guidance for conducting Cybersecurity Maturity Model Certification (CMMC) assessments for Level 2.

• Cybersecurity and Infrastructure Security Agency – More than a password
  CISA's guide for getting started with MFA in your business and personal life.

• CyberSheath- How Multi-Factor Authentication Protects Your Business
  This article highlights MFA and the necessity to implement to all privileged account access and users who access network resources.

• Duo – Best practices for securing a Duo MFA enrollment Rollout
  This guide aims to aid existing and new Duo customers in securing their MFA rollout at their respective organizations.

• Duo – Two-Factor Authentication Evaluation Guide
  Learn what to look for when assessing and comparing two-factor authentication solutions.

• Duo Multi-Factor Authentication
  Duo's wide variety of authentication methods make it easy for every user to securely and quickly log in.

• Gartner – User Authentication Product Reviews and Ratings
  Gartner's user authentication product reviews and ratings

• Microsoft – Authentication Methods for AD FS
  Guide to enable Multi-factor authentication for Active Directory Federation Services (AD FS) in Windows Server. Also provide guides for use of common Third-party authentication methods (i.e., Duo, Akamai, RSA, etc.,)

• Microsoft – Set up Multi-Factor Authentication for M365
  Guide for enforcing MFA for Microsoft 365

• NIST SP 800-53: IA-2 Identification and Authentication (Organization Users)
  Control objectives for the implementation of multi-factor authentication from NIST SP 800-53.

• NordLayer – The importance of multi-factor authentication for remote access
  This blog post describes why multifactor authentication (MFA) is important for remote access.

• RCDevs
  OpenOTP is a phishing-resistant MFA solution.

• RSA SecurID Access
  Secure access to your extended enterprise with RSA SecurID Access, the leading multi-factor authentication and identity assurance solution.

• SANS Whitepaper – Two-Factor Authentication: Can You Choose the Right One?
  This SANS whitepaper focuses on enterprise solutions for two-factor authentication.

• Schneier on Security – More on Two-Factor Authentication
  More on Two-Factor Authentication and its ineffectiveness defense against identity theft.

• State of Georgia – System Maintenance Policy
  This example policy from the State of Georgia provides a starting point for system maintenance.

• Symantec Whitepaper – Two-Factor Authentication
  This whitepaper is directed at IT, Security, and Compliance workers who are responsible for recommending or evaluating security products; or running and managing two-factor authentication infrastructure.

• Thales
  Gemalto's identity and access management (IAM) solutions allow organizations to meet the evolving needs around cloud applications and mobile devices.

• YouTube – NIST SP 800-171 Control 3.5.3 Use multifactor authentication for access to privileged accounts
  In this edition of the On Call Compliance Solutions Compliance Tip of the Week, we discuss how 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). Let’s talk about NIST 800-171 Control 3.5.3 Use multifactor authentication for local and network access to privileged accounts and for network access to non-privileged accounts.

• Yubico
  Yubikey is a phishing-resistant MFA that stops modern cyber-attacks.

Discussion [NIST SP 800-171 R2]

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.

Further 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.