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 03.07.05 Nonlocal Maintenance

Nonlocal maintenance and diagnostic activities are those activities conducted by individuals communicating through an external network. The authentication techniques employed in the establishment of these nonlocal maintenance and diagnostic sessions reflect the network access requirements in 03.05.03.

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

Nonlocal maintenance activities must use multifactor authentication. Multifactor authentication requires at least two factors, such 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 fingerprint or facial scan).

Requiring two or more factors to prove your identity increases the security of the connection. Nonlocal maintenance activities are activities conducted from external network connections such as over the internet. After nonlocal maintenance activities are complete, shut down the external network connection. This requirement, MA.L2-3.7.5 specifies the addition of multifactor authentication for remote maintenance sessions 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 IA.L2-3.5.3):

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 session.

Finally, IA.L2-3.5.3 requires multifactor authentication for network access to nonprivileged accounts.

Examples

  1. Example 1

    You are responsible for maintaining your company’s firewall. In order to conduct maintenance while working remotely, you connect to the firewall’s management interface and log in using administrator credentials. The firewall then sends a verification request to the multifactor authentication app on your smartphone [a]. You need both of these things to prove your identity [a]. After you respond to the multifactor challenge, you have access to the maintenance interface. When you finish your activities, you shut down the remote connection by logging out and quitting your web browser [b].

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 system maintenance 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.
  • Organizational processes for managing nonlocal maintenance
  • Mechanisms implementing, supporting, and managing nonlocal maintenance
  • Mechanisms for strong authentication of nonlocal maintenance diagnostic sessions
  • Mechanisms for terminating nonlocal maintenance sessions and network connections

Potential Assessment Considerations

  • Is multifactor authentication required prior to maintenance of a system when connecting remotely from outside the system boundary [a]?
  • Are personnel required to manually terminate remote maintenance sessions established via external network connections when maintenance is complete, or are connections terminated automatically through system session management mechanisms [b]?

Key References

NIST SP 800-171 Rev. 2 3.7.5

Evidence

  1. 03.07.05.a

    Multifactor authentication is used to establish nonlocal maintenance sessions via external network connections

  1. 03.07.05.b

    Nonlocal maintenance sessions established via external network connections are terminated when nonlocal maintenance is complete