DISCUSSION [NIST SP 800-171 R2]

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.

FURTHER 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].

Potential Considerations

Are user accounts or identifiers monitored for inactivity [b]?42

Copyright

Copyright 2020, 2021 Carnegie Mellon University and The Johns Hopkins University Applied Physics Laboratory LLC.

Copyright 2021 Futures, Inc.

This material is based upon work funded and supported by the Department of Defense under Contract No. FA8702-15-D-0002 with Carnegie Mellon University for the operation of the Software Engineering Institute, a federally funded research and development center, and under Contract No. HQ0034-13-D-0003 and Contract No. N00024-13-D-6400 with the Johns Hopkins University Applied Physics Laboratory LLC, a University Affiliated Research Center.

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