AC-7(4) Unsuccessful Logon Attempts | Use of Alternate Authentication Factor
(a) Allow the use of organization-defined authentication factors that are different from the primary authentication factors after the number of organization-defined consecutive invalid logon attempts have been exceeded; and (b) Enforce a limit of organization-defined number consecutive invalid logon attempts through use of the alternative factors by a user during a organization-defined time period.
Source: NIST SP 800-53 Rev 5, AC-7(4). The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open NIST SP 800-53 Rev 5 in the compliance library.
Base controls and their enhancements. Which apply follows the baseline you are assessed against (for example FedRAMP Moderate or High, or the low, moderate and high baselines of SP 800-53B). Text in square brackets is a parameter your organisation sets.
These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.
system holds itEvidence a system already holds
none for this control
periodic reviewEvidence produced at each review
- System audit records · Identity provider / directory
- Test of Mechanisms implementing access control policy for unsuccessful logon attempts · Identity provider / directory
governing documentDocuments that govern the control
- Access control policy · Policy repository / GRC workspace
- Procedures addressing unsuccessful logon attempts for primary and alternate authentication factors · Policy repository / GRC workspace
- System design documentation · Policy repository / GRC workspace
- System configuration settings and associated documentation · Policy repository / GRC workspace
- System security plan · Policy repository / GRC workspace
First move
Common gaps auditors find
- No alternate authentication factor is available after the invalid logon limit is exceeded
- Consecutive invalid attempts using the alternative factors are not limited as required by (b)
Do this for your whole sheet
Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.
Build my evidence sheetAC-7(3) Unsuccessful Logon Attempts | Biometric Attempt Limiting · AC-8 System Use Notification