NIST SP 800-171

Control 3.4.6

Employ Least Functionality

CMMC-RP Certified Team 24+ Years Experience CMMC-AB RPO #1449

Official Requirement

Employ the principle of least functionality by configuring organizational information systems to provide only essential capabilities.

What This Means in Plain English

Systems should only have the software, services, and functions that are needed for their purpose. Unnecessary programs, services, and features should be disabled or removed to reduce the attack surface.

How Petronella Implements This Control

Petronella Technology Group implements this control through:

  • Standard OS images with only required applications and services enabled
  • Group Policy disabling unnecessary Windows features and services on workstations
  • Server roles configured with only the required services (no extra roles installed)
  • Sophos XDR application control blocking unapproved applications
  • Regular review of installed software and running services against approved baselines

Assessment Guidance

Assessors will review system configurations for unnecessary services and features, verify that application whitelisting or control is enforced, check that standard images include only required software, and test for running services that are not required for the system's function.

Common Implementation Gaps

  • Default OS installation with all features enabled
  • Unnecessary services running on servers (FTP, Telnet, print services)
  • Users able to install any software on their workstations
  • No application whitelisting or control
  • No periodic review of installed software and running services

Cross-Framework Mapping

FrameworkMapped Controls
NIST SP 800-53CM-7
PCI DSSReq 2.2.2 - Enable only necessary services, protocols, daemons, and functions
CP
By Craig Petronella
Founder, Petronella Technology Group | CMMC-RP (RPO #1449) | DFE #604180 | MIT-Certified in AI and Blockchain
Craig has helped North Carolina defense contractors prepare for CMMC assessments since 2002 and authored the CMMC 2.0 Certification Guide. Read the LinkedIn profile or verify the RPO listing at the CyberAB Marketplace.

Need Help Implementing 3.4.6?

Our CMMC-RP certified team can assess your current compliance posture and build a remediation plan.

Schedule a Compliance Assessment Calculate your SPRS score