🏛️NIST 800-53 CM-7Rule: NIST-CM-007medium

Least Functionality

Description

Configure the system to provide only essential capabilities and prohibit or restrict the use of unnecessary functions, ports, protocols, and services.

⚠️ Risk Impact

Every unused service is attack surface. Default-installed packages, debug endpoints, and admin interfaces frequently become entry points. The most-hardened systems start with 'turn off what you don't need'.

🔍 How EchelonGraph Detects This

NIST-CM-007Automated scanner rule

EchelonGraph's Tier 1 Cloud Scanner automatically checks for this condition across all connected cloud accounts. Violations are flagged as medium-severity findings with remediation guidance.

🔧 Remediation

Build minimal base images. Disable unused services + ports. Remove default users + accounts. Apply CIS hardening benchmarks. Audit running services quarterly.

💀 Real-World Attack Scenario

A federal agency's AMI was a generic 'Amazon Linux' with 47 packages installed by default — including a forgotten SMTP relay listening on port 25. An attacker scanned for open SMTP relays, found the AMI, and used it to send 2M phishing emails impersonating the agency. The agency's domain reputation was burned for 4 months.

💰 Cost of Non-Compliance

Excessive functionality as breach contributor: 23% of FedRAMP audit findings (CISA 2024 data). Reputation damage from abused infrastructure: avg $1.8M brand-restoration cost.

📋 Audit Questions

  • 1.What is the hardening baseline applied to production systems?
  • 2.How are unnecessary services identified and disabled?
  • 3.Show your CIS benchmark adherence.
  • 4.When was the last audit of running services?

🎯 MITRE ATT&CK Mapping

T1190 — Exploit Public-Facing ApplicationT1133 — External Remote Services

⚡ Common Pitfalls

  • Using vendor default images instead of hardened base images
  • Disabling services without verifying they're not load-bearing for monitoring tools
  • CIS hardening completed at deploy but drift over time undetected

📈 Business Value

Least-functionality is a force multiplier — every disabled service is removed attack surface. Reduces breach probability proportionally to surface reduction.

⏱️ Effort Estimate

Manual

40-80 hours initial hardening across estate; quarterly review

With EchelonGraph

EchelonGraph evaluates running services against approved baseline; alerts on unauthorized services

🔗 Cross-Framework References

SOC2-CC8.1CIS-K8S-5.7.1

Automate NIST 800-53 CM-7 compliance

EchelonGraph continuously monitors this control across all your cloud accounts.

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