EIDCA-018: Managed Device Required for MFA Registration

Platform
Entra ID / M365
Category
Entra ID Conditional Access
Severity
Medium
Zero Trust pillar
Identity (weight 3)
Golden fixtures
3
Branch coverage
Observed: fixtures prove the verdicts they exercise
Provenance
baseline

What it checks

Requiring an agency-managed (compliant or Hybrid Entra joined) device for the security-information registration action reduces the risk of an adversary using stolen credentials to enroll their own MFA method and establish persistence. SCuBA recommends that managed devices be required to register MFA. This is implemented as a Conditional Access policy targeting the 'Register security information' user action and requiring a compliant device or Hybrid Entra ID joined device as a grant control. This check inspects enabled Conditional Access policies for that configuration.

Recommended value

An enabled Conditional Access policy targets the security-information registration user action and requires a compliant or Hybrid Entra ID joined device

Remediation

Create a Conditional Access policy to require a managed device for MFA registration, satisfying SCuBA MS.AAD.3.8. Target the user action 'Register security information', scope it to all users (excluding break-glass accounts), and set the grant control to require a compliant device or Hybrid Entra ID joined device. Pilot in report-only mode, ensure a bootstrap path exists for new devices (for example Temporary Access Pass), then enable enforcement.

Fixture-proven verdicts

Every verdict below is proven by a golden fixture in the module's gating test suite. This table derives from the last green run; it cannot be edited by hand.

Verdict scenarios for EIDCA-018
ScenarioExpected verdict
cleanPASS
known-badFAIL
no-dataNot Assessed

Framework mappings

CISA SCuBA
MS.AAD.3.8v1
NIST SP 800-53
IA-2(1), IA-5, AC-19
MITRE ATT&CK
T1556.006