3.8.7Control removable media
Decide whether USB storage is allowed at all, and enforce that.
The requirement, verbatim
NIST SP 800-171 Rev. 2 · 3.8.7Control the use of removable media on system components.
NIST's discussion
In contrast to requirement MP.L2-3.8.1, which restricts user access to media, this requirement restricts the use of certain types of media on systems, for example, restricting or prohibiting the use of flash drives or external hard disk drives. Organizations can employ technical and nontechnical controls (e.g., policies, procedures, and rules of behavior) to control the use of system media. Organizations may control the use of portable storage devices, for example, by using physical cages on workstations to prohibit access to certain external ports, or disabling or removing the ability to insert, read, or write to such devices.
Organizations may also limit the use of portable storage devices to only approved devices including devices provided by the organization, devices provided by other approved organizations, and devices that are not personally owned. Finally, organizations may control the use of portable storage devices based on the type of device, prohibiting the use of writeable, portable devices, and implementing this restriction by disabling or removing the capability to write to such devices. Malicious code protection mechanisms include anti-virus signature definitions and reputation-based technologies. Many technologies and methods exist to limit or eliminate the effects of malicious code. Pervasive configuration management and comprehensive software integrity controls may be effective in preventing execution of unauthorized code. In addition to commercial off-the-shelf software, malicious code may also be present in custom-built software. This could include logic bombs, back doors, and other types of cyber-attacks that could affect organizational missions/business functions. Traditional malicious code protection mechanisms cannot always detect such code. In these situations, organizations rely instead on other safeguards including secure coding practices, configuration management and control, trusted procurement processes, and monitoring technologies to help ensure that software does not perform functions other than the functions intended.
NIST SP 800-171 Rev. 2, discussion under 3.8.7. Whitespace normalised; wording unchanged.
Assessment objectives
An assessor decides each of these separately. The requirement is met only when every objective is.
- [a] the use of removable media on system components is controlled
NIST SP 800-171A, determination statements for 3.8.7.
For assessors: examine, interview, test
NIST SP 800-171A names what an assessor may examine, whom they may interview, and what they may test for this requirement. Assessors select from these lists; they are not a checklist of everything you must produce.
Examine
- System media protection policy
- system use policy
- procedures addressing media usage restrictions
- system security plan
- rules of behavior
- system design documentation
- system configuration settings and associated documentation
- system audit logs and records
- other relevant documents or records
Interview
- Personnel with system media use responsibilities
- personnel with information security responsibilities
- system or network administrators
Test
- Organizational processes for media use
- mechanisms restricting or prohibiting use of system media on systems or system components
NIST SP 800-171A, potential assessment methods and objects for 3.8.7.
Evidence
No evidence examples are published for this requirement yet. The objectives above are what an assessor checks; evidence is whatever shows each one is true in your environment, dated and kept with your system security plan.
Scoring weight
Worth 5 points. Not meeting this requirement subtracts 5 from your 110-point SPRS score. These are the requirements with the largest effect on your posture.
DoD NIST SP 800-171 Assessment Methodology v1.2.1 weighting, as carried in the Bedrock scoring table. The score starts at 110 and subtracts the weight of every requirement not met.
In Rev. 3
Rev. 2 is what your contract requires today. A standing DoD class deviation keeps Rev. 2 in force; NIST has published Rev. 3, but it is not adopted for contracts. In Rev. 3 this requirement is reworded: 03.08.07 Media Use. It gains organization-defined parameters.
See the Rev. 2 and Rev. 3 wording word by word, or start with the status page.
Related requirements
Where this page's facts come from
- Requirement text
- bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.basicRequirement@rev2
- Discussion
- bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.discussion@rev2
- Practice name
- bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.title@rev2 (CMMC Assessment Guide practice name)
- Objectives
- bedrock-cmmc-api@89b8e8e:migrations/005_reference_objectives.sql#AssessmentObjective.description@rev2
- Examine, interview, test
- bedrock-cmmc-api@89b8e8e:migrations/005_reference_objectives.sql#AssessmentObjective.description@rev2 ({examineGuidance, interviewGuidance, testGuidance})
- Level
- bedrock-cmmc-api@89b8e8e:migrations/021_fix_level1_requirements.sql#Requirement.cmmcLevel@rev2
- Weight
- bedrock-cmmc-api@89b8e8e:internal/cmmc/requirement_values.go#requirementValues (DoD AM v1.2.1 / eMASS L2 template v3.8)
- Rev. 3 mapping
- bedrock-cmmc-api@89b8e8e:docs/reference/nist-800-171-rev3/normalized/r2_r3_transition_map.json#r2_to_r3
- Plain-language title and summary
- editorial/CMMC Navigator.dc.html#RAW (Foxx Cyber editorial)