CPCSC Level 2 Control

Last updated June 25, 2026

03.04.06Configuration management

CPCSC Level 2 03.04.06: Least Functionality

Apply least functionality to keep systems configured, changed, inventoried, and hardened in a controlled way for CPCSC Level 2 readiness. This guide separates the official ITSP.10.171 control language from practical implementation, evidence, auditor questions, and related controls.

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Formal Control Language

Official ITSP.10.171 wording for 03.04.06. Use the Cyber Centre publication and contract requirements as the source of truth for certification, assessment, or procurement submissions.

  • Configure the system to provide only mission-essential capabilities
  • Prohibit or restrict use of the following functions, ports, protocols, connections, and services: [Assignment: organization-defined functions, ports, protocols, connections, and services]
  • Review the system [Assignment: organization-defined frequency] to identify unnecessary or nonsecure functions, ports, protocols, connections, and services
  • Disable or remove functions, ports, protocols, connections, and services that are unnecessary or nonsecure

Contains information sourced from Government of Canada material used under the Open Government Licence - Canada.

What This Means In Plain English

Least Functionality is part of the CPCSC Level 2 Configuration management family. This is about knowing what a secure configuration looks like and controlling how systems move away from that baseline.

For a founder, CISO, engineer, or compliance owner, the practical question is whether least functionality is visible in real operating evidence: a setting, workflow, ticket, log, approval, review, or exception record that can survive an external assessment.

Level 2 is different from Level 1 because the evidence has to survive an external assessment. A policy statement helps, but the stronger answer is a record that shows who did the work, when it ran, what system setting or workflow enforced it, and how exceptions were handled.

How To Implement It

1

Define the in-scope systems, owners, users, vendors, and data flows affected by least functionality.

2

Create baselines for in-scope systems, track inventory, review changes, restrict configuration access, and remove unnecessary software and services.

3

Translate the formal requirement into one or two operating procedures: who performs it, how often, where it is recorded, and who approves exceptions.

4

Configure the relevant systems so the control is enforced by identity, endpoint, cloud, network, ticketing, monitoring, vendor, or documentation workflows rather than memory.

5

Keep evidence in a consistent folder, GRC system, ticket queue, or audit workspace so an assessor can trace the control from requirement to implementation to review.

Evidence Normally Gathered

Least Functionality: baseline configuration documents.

Least Functionality: change tickets.

Least Functionality: asset inventory.

Least Functionality: configuration screenshots.

Least Functionality: software allowlist or inventory.

Least Functionality: exception records.

Least Functionality: owner assignment and review cadence.

Least Functionality: exception, remediation, or POA&M records when the control is not fully implemented.

Common Auditor Questions

Where is least functionality implemented in the in-scope environment?

Who owns least functionality, and how do they know it is operating?

Show the evidence that proves least functionality ran during the assessment period.

What happens when least functionality fails, is bypassed, or has an exception?

How does this control connect to the system security plan, risk register, POA&M, and related CPCSC controls?

Sources

Source and attribution.

Formal control language is sourced from the Canadian Centre for Cyber Security ITSP.10.171 publication. CPCSC Level 2 assessment context references the Government of Canada CPCSC program overview and ITSP.10.171-01 assessment guidance.

CPCSC Program OverviewITSP.10.171ITSP.10.171-01Open Government Licence - Canada