Overview

Security Requirements for 03.01.21 Portable Storage Use

Limits on the use of organization-controlled portable storage devices in external systems include complete prohibition of the use of such devices or restrictions on how the devices may be used and under what conditions the devices may be used. Note that while “external” typically refers to outside of the organization’s direct supervision and authority, that is not always the case. Regarding the protection of CUI across an organization, the organization may have systems that process CUI and others that do not. Among the systems that process CUI there are likely access restrictions for CUI that apply between systems. Therefore, from the perspective of a given system, other systems within the organization may be considered “external" to that system.

Assessment GuidanceExamine 0/7

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

Discussion

A portable storage device is a system component that can be inserted or attached and easily removed from a system. It is used to store data or information. Examples of portable storage devices include:

compact/digital video disks (CDs/DVDs); Universal Serial Bus (USB) drives; external hard disk drives;

flash memory cards/drives; and floppy disks.

This requirement can be implemented in two ways:

identifying the portable storage device usage restrictions, identifying portable storage devices that may be used on external systems, identifying associated external systems on which a portable storage device may be used, and administratively (through the use of a written policy) limiting the usage of the devices to those systems; or

configuring devices to work only when connected to a system to which the portable storage device can authenticate, limiting the devices’ use on external systems to those that the OSA has the ability to manage.

Examples

  1. Example 1

    Your organization, which stores and processes CUI, has a written portable device usage restriction policy. It states that users can only use external storage devices such as thumb dives or external hard disks that belong to the company. When needed for a specific business function, a user checks the device out from IT and returns it to IT when no longer needed [a, 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 responsibilities for restricting or prohibiting use of organization-controlled storage devices on external systems
  • System or network administrators
  • Personnel with information security responsibilities
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 implementing restrictions on use of portable storage devices

Potential Assessment Considerations

  • Are the portable storage devices authorized for external use identified and documented [a]?
  • Are the circumstances defined in which portable storage devices containing CUI may be used on external systems (e.g., with management approval) [b]?
  • Are limitations stipulated for the use of portable storage devices containing CUI on external systems (e.g., authorized personnel only, encrypted drives required) [b]?

Key References

NIST SP 800-171 Rev. 2 3.1.21

Evidence

  1. 03.01.21.a

    The use of portable storage devices containing cui on external systems is identified and documented

  1. 03.01.21.b

    Limits on the use of portable storage devices containing cui on external systems are defined

  1. 03.01.21.c

    The use of portable storage devices containing cui on external systems is limited as defined