← AC-7
AC-7(4) AC · Access Control

Use of Alternate Authentication Factor

LOW MODERATE HIGH
1 Overlay 1 Related Control
Graph
Export ▾

Requirements NIST SOURCE

Discussion (NIST Supplemental Guidance)

The use of alternate authentication factors supports the objective of availability and allows a user who has inadvertently been locked out to use additional authentication factors to bypass the lockout.

Implementation Guidance

Engineering Interpretation

Original engineering commentary written for this explorer — not NIST source text and not authoritative guidance.

No engineering interpretation has been authored for AC-7(4) yet. This section is architected to receive it — see the Requirements and Assessment sections above for the authoritative NIST source content in the meantime.

Assessment

NIST SP 800-53A REV 5.2.0

Assessment Objectives

  1. authentication factors allowed to be used that are different from the primary authentication factors are defined;
  2. the number of consecutive, invalid logon attempts through the use of alternative factors for which to enforce a limit by a user is defined;
  3. time period during which a user can attempt logons through alternative factors is defined;
  4. <AC-07(04)_ODP[01] authentication factors> that are different from the primary authentication factors are allowed to be used after the number of organization-defined consecutive invalid logon attempts have been exceeded;
  5. a limit of <AC-07(04)_ODP[02] number> consecutive invalid logon attempts through the use of the alternative factors by the user during a <AC-07(04)_ODP[03] time period> is enforced.

Examine

[SELECT FROM: Access control policy; procedures addressing unsuccessful logon attempts for primary and alternate authentication factors; system design documentation; system configuration settings and associated documentation; system audit records; system security plan; other relevant documents or records].

Interview

[SELECT FROM: System/network administrators; organizational personnel with information security responsibilities].

Test

[SELECT FROM: Mechanisms implementing access control policy for unsuccessful logon attempts].

Overlays

Showing the OT/ICS overlay for the parent control AC-7 — see the AC-7(4) entries within each baseline below.

OT/ICS Overlay SP 800-82r3

NIST SP 800-82r3 Appendix F, Table 22. Blank baseline means the control/control enhancement is not selected in that initial OT baseline.

LOW

  • Base control: Included (matches standard baseline)

MODERATE

  • Base control: Included (matches standard baseline)

HIGH

  • Base control: Included (matches standard baseline)

STIGs & CCIs

No STIG checks or CCI mappings are currently loaded for AC-7(4). This section is architected to display, per product: STIG ID, Finding ID, Severity, Title, Description, Check, Fix, CCI, and NIST control mapping — but nothing is populated here until a real DISA STIG/CCI dataset is ingested.

Learn more about STIG/CCI integration →

Evidence

Potential Evidence — Derived

Categorized from the SP 800-53A "Examine"/"Test" artifact list above by keyword — not an authoritative NIST evidence list.

Policy

  • Access control policy
  • system security plan

Configuration

  • system design documentation
  • system configuration settings and associated documentation

Testing

  • Mechanisms implementing access control policy for unsuccessful logon attempts

Other Records

  • procedures addressing unsuccessful logon attempts for primary and alternate authentication factors
  • system audit records
  • other relevant documents or records