Overview

Security Requirements for 03.05.06 Identifier Handling

Inactive identifiers pose a risk to organizational information because attackers may exploit an inactive identifier to gain undetected access to organizational devices. The owners of the inactive accounts may not notice if unauthorized access to the account has been obtained.

Assessment GuidanceExamine 0/9

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

Discussion

Identifiers are uniquely associated with an individual, account, process, or device. An inactive identifier is one that has not been used for a defined extended period of time. For example, a user account may be needed for a certain time to allow for transition of business processes to existing or new staff. Once use of the identifier is no longer necessary, it should be disabled as soon as possible. Failure to maintain awareness of accounts that are no longer needed yet still active could allow an adversary to exploit IT services.

Example One of your responsibilities is to enforce your company’s inactive account policy: any account that has not been used in the last 45 days must be disabled [a]. You enforce this by writing a script that runs once a day to check the last login date for each account and generates a report of the accounts with no login records for the last 45 days. After reviewing the report, you notify each inactive employee’s supervisor and disable the account [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 identifier management responsibilities
  • Personnel with information security responsibilities
  • System or network administrators
  • System developers
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 identifier management

Potential Assessment Considerations

  • Are user accounts or identifiers monitored for inactivity [b]?

Key References

NIST SP 800-171 Rev. 2 3.5.6

Evidence

  1. 03.05.06.a

    A period of inactivity after which an identifier is disabled is defined

  1. 03.05.06.b

    Identifiers are disabled after the defined period of inactivity