CIS Controls v8 6.3 — Require MFA for Externally-Exposed Applications

What this control requires

Require all externally-exposed enterprise or third-party applications to enforce MFA, where supported. Enforcing MFA through a directory service or SSO provider is a satisfactory implementation of this Safeguard.

In plain English

Require all externally-exposed enterprise or third-party applications to enforce MFA, where supported. In practice, this means you can prove you enforce applications-level controls on a defined cadence.

Why it matters

The CIS Controls are an industry-vetted, prioritised defence: skipping a safeguard widens the attack surface that the safeguards above and below it assume is closed. Audit frameworks (FedRAMP, PCI DSS, HIPAA) all cite CIS as evidence of due care.

This control is rated critical in the source catalogue. Treat gaps here as production incidents in the risk register, not housekeeping.

What an auditor looks for

A CIS-aligned reviewer wants to see (a) which Implementation Group you are targeting, (b) a documented owner for the safeguard, and (c) a tooling or process artefact (config, scan output, ticket) that proves the safeguard runs on the cadence the control demands.

Within Protect, the assessor will trace your implementation back to the catalogue reference (Control 6.3) and look for objective evidence on the latest two assessment cycles.

How to implement

1. Write a short policy stating intent, scope and named owner.
2. Encode it as a platform guardrail — SCP, Azure Policy initiative, Organisation Policy, or repository policy.
3. Wire a monitoring signal that catches drift (CSPM rule, SIEM rule, scheduled query, Workspace alert) and ticket it.
4. Review on a documented cadence and capture the review in the risk register or compliance tracker.

Operational checklist

• Enforce. Document the trigger, the owner and the cadence.
• Require. Document the trigger, the owner and the cadence.
• Protect. Document the trigger, the owner and the cadence.
• Scope: applications, service, mfa, identity management, enterprise.

Evidence to collect

• Identity Scan. IAM / IdP exports — Entra ID, Okta, IAM Identity Center, Workspace directory — showing accounts, roles, MFA state and last sign-in.
• Vendor Risk Management. vendor_risk_management evidence

Identity analytics (Okta, SailPoint, Access Analyzer) demonstrates least-privilege. Third-party risk management evidence (assessments, contracts, due diligence) shows supplier oversight. Focus: Require MFA for Externally-Exposed Applications.

How it maps to other frameworks

Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit.

• ISO/IEC 27001:2022 A.8.23 — Web filtering
• ISO/IEC 27701:2025 A.3.8 — Identity management
• SOC 2 (2017 TSC) CC1.5 — Accountability for Internal Control Responsibilities
• NIST SP 800-171 Rev. 3 3.13.4 — Information in Shared System Resources
• NIST SP 800-53 Rev. 5 AC-3(12) — Assert And Enforce Application Access

Related controls in CIS Controls v8

• Control 6.5 — Require MFA for Administrative Access
• Control 6.6 — Establish and Maintain an Inventory of Authentication and Authorization Systems
• Control 9.2 — Use DNS Filtering Services
• Control 6.7 — Centralize Access Control
• Control 5.6 — Centralize Account Management
• Control 5.2 — Use Unique Passwords

References

• Center for Internet Security — CIS Controls v8
• Catalogue identifier: Control 6.3

Topics: identity accessvendor riskidentity managementvendor managementaccess reviewprivileged access