Security requirement
- a.Approve, control, and monitor the use of system maintenance tools.
- b.Check media with diagnostic and test programs for malicious code before it is used in the system.
- c.Prevent the removal of system maintenance equipment containing CUI by verifying that there is no CUI on the equipment, sanitizing or destroying the equipment, or retaining the equipment within the facility.
Discussion
Approving, controlling, monitoring, and reviewing maintenance tools address security-related issues associated with the tools that are used for diagnostic and repair actions on the system. Maintenance tools can include hardware and software diagnostic and test equipment as well as packet sniffers. The tools may be pre-installed, brought in with maintenance personnel on media, cloud-based, or downloaded from a website. Diagnostic and test programs are potential vehicles for transporting malicious code into the system, either intentionally or unintentionally. Examples of media inspection include checking the cryptographic hash or digital signatures of diagnostic and test programs and media. If organizations inspect media that contain diagnostic and test programs and determine that the media also contain malicious code, the incident is handled consistent with incident handling policies and procedures. A periodic review of system maintenance tools can result in the withdrawal of approval for outdated, unsupported, irrelevant, or no-longer-used tools. Maintenance tools do not address the hardware and software components that support maintenance and are considered a part of the system.
Implementation perspective
Treat Maintenance Tools as a CUI protection outcome that must be reflected in the system boundary, documented implementation, operational behavior, and assessment evidence. Pay particular attention to authorized maintenance, trusted tools, controlled support access, and protection of CUI during repair or servicing.
- 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
- maintenance schedules and tickets
- tool approval records
- remote maintenance session logs
- maintenance personnel authorization
Common failure patterns
- vendor access left enabled permanently
- unapproved diagnostic tools introduced
- maintenance bypassing change control
- remote sessions not monitored or terminated
Assessment objectives and methods
Assessment objectives (5)
- a.
the use of system maintenance tools is approved.
- a.
the use of system maintenance tools is controlled.
- a.
the use of system maintenance tools is monitored.
- b.
media with diagnostic and test programs are checked for malicious code before the media are used in the system.
- c.
the removal of system maintenance equipment containing CUI is prevented by verifying that there is no CUI on the equipment, sanitizing or destroying the equipment, or retaining the equipment within the facility.
Examine
- maintenance policy and procedures
- procedures for system maintenance tools
- system maintenance tools
- maintenance tool inspection records
- equipment sanitization records
- media sanitization records
- system security plan
- other relevant documents or records
Interview
- personnel with system maintenance responsibilities
- personnel responsible for media sanitization
- personnel with information security responsibilities
Test
- processes for approving, controlling, and monitoring maintenance tools
- mechanisms for supporting or implementing the approval, control, or monitoring of maintenance tools
- processes for preventing the unauthorized removal of information
- processes for inspecting media for malicious code
- mechanisms for supporting media sanitization or the destruction of equipment
- mechanisms for supporting the verification of media sanitization
- processes for inspecting maintenance tools
- mechanisms for supporting or implementing the inspection of maintenance tools
- mechanisms for supporting or implementing the inspection of media used for maintenance
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.