NIST 800-171 · Access Control

Requirement 3.1.21

SPRS weight
SPRS weight: 1
POA&M eligibility
POA&M-eligible
Assessment objectives
3 assessment objectives

Official requirement text

Limit use of portable storage devices on external systems.

Assessment objectives

Assessors don’t evaluate the requirement as one sentence; they walk these objectives one by one. Each must be met for the requirement to score.

  1. 3.1.21[a]use of organizational portable storage devices containing CUI on external systems is identified and documented.
  2. 3.1.21[b]limits on the use of organizational portable storage devices containing CUI on external systems are defined.
  3. 3.1.21[c]use of organizational portable storage devices containing CUI on external systems is limited as defined.

Inside Valontir, this requirement carries a full plain-English guide: what it asks in normal words, what good looks like in a small shop, the evidence an assessor accepts, the common gaps that cost points, and a plain reading of every assessment objective shown above. See it in a demo.

NIST 800-171 3.1.21 explained — Access Control | Valontir