Security requirement
- a.Establish usage restrictions, configuration requirements, and connection requirements for mobile devices.
- b.Authorize the connection of mobile devices to the system.
- c.Implement full-device or container-based encryption to protect the confidentiality of CUI on mobile devices.
Discussion
A mobile device is a computing device with a small form factor such that it can be carried by a single individual; is designed to operate without a physical connection; possesses local, non-removable, or removable data storage; and includes a self-contained power source. Mobile device functionality may include on-board sensors that allow the device to capture information, voice communication capabilities, and/or built-in features for synchronizing local data with remote locations. Examples include smart phones, smart watches, and tablets. Mobile devices are typically associated with a single individual. The processing, storage, and transmission capabilities of mobile devices may be comparable to or a subset of notebook or desktop systems, depending on the nature and intended purpose of the device. Some organizations may consider notebook computers to be mobile devices. The protection and control of mobile devices are behavior- or policy-based and require users to take physical action to protect and control such devices when outside of controlled areas. Controlled areas are spaces for which the organization provides physical or procedural controls to meet the requirements established for protecting CUI. Due to the large variety of mobile devices with different characteristics and capabilities, organizational restrictions may vary for the different classes or types of such devices. Usage restrictions, configuration requirements, and connection requirements for mobile devices include configuration management, device identification and authentication, implementing mandatory protective software, scanning devices for malicious code, updating virus protection software, scanning for critical software updates and patches, conducting operating system and possibly other software integrity checks, and disabling unnecessary hardware. On mobile devices, secure containers provide software-based data isolation designed to segment enterprise applications and information from personal apps and data. Containers may present multiple user interfaces, one of the most common being a mobile application that acts as a portal to a suite of business productivity apps, such as email, contacts, and calendar. Organizations can employ full-device encryption or container-based encryption to protect the confidentiality of CUI on mobile devices.
Implementation perspective
Treat Access Control for Mobile Devices as a CUI protection outcome that must be reflected in the system boundary, documented implementation, operational behavior, and assessment evidence. Pay particular attention to approved identities, least privilege, remote access, information flow, and the full account lifecycle.
- Confirm the requirement is in scope for the CUI system components, services, users, and external connections being assessed.
- Resolve every organization-defined parameter through an approved governance and tailoring process.
- Map each clause of the requirement to an accountable owner, implementation mechanism, and evidence source.
- Verify that inherited and shared implementations are supported by current provider evidence and responsibility boundaries.
- Collect evidence during normal operation and review changes, exceptions, and deficiencies on a risk-based cadence.
Questions to ask
- Which CUI assets, data flows, users, and services are protected by this requirement?
- Which portions are implemented locally, inherited, shared, or not applicable, and what evidence supports that determination?
- Do the system security plan, deployed configuration, operating process, and assessment evidence tell the same story?
- What change, incident, or threshold should trigger reassessment?
Evidence and validation
- access authorization and approval records
- account inventories and entitlement exports
- access review results
- authentication and authorization logs
Common failure patterns
- CUI access that exceeds mission need
- shared or orphaned accounts
- remote access paths outside the approved boundary
- access reviews that cannot be reconciled to deployed permissions
Assessment objectives and methods
Assessment objectives (5)
- a.
usage restrictions are established for mobile devices.
- a.
configuration requirements are established for mobile devices.
- a.
connection requirements are established for mobile devices.
- b.
the connection of mobile devices to the system is authorized.
- c.
full-device or container-based encryption is implemented to protect the confidentiality of CUI on mobile devices.
Examine
- access control policy and procedures
- procedures for mobile device access control
- system design documentation
- configuration management plan
- system configuration settings
- authorizations for mobile device connections to organizational systems
- system audit records
- encryption mechanisms and associated configuration documentation
- system security plan
- other relevant documents or records
Interview
- personnel with access control responsibilities for mobile devices
- personnel using mobile devices to access organizational systems
- personnel with information security responsibilities
- system administrators
Test
- access control capability for mobile device connections to organizational systems
- encryption mechanisms for protecting the confidentiality of CUI on mobile devices
- configurations of mobile devices
Source NIST SP 800-53 controls
These controls are referenced by the official SP 800-171 Rev. 3 OSCAL record. Open the corresponding control pages for complete control text, enhancements, D3FEND mappings, and related learning.
Authoritative sources
- NIST SP 800-171 Revision 3 official publication ↗
- NIST SP 800-171A Revision 3 official publication ↗
- NIST OSCAL Content release used for this import ↗
Bare Metal Cyber is an independent educational publisher and is not affiliated with or endorsed by NIST. The official publications, the responsible federal agency, and the governing contract or agreement determine applicability, tailoring, assessment depth, and required implementation.