EIDCA-008: Legacy Authentication Blocking via CA
- Plataforma
- Entra ID / M365
- Categoría
- Entra ID Conditional Access
- Severidad
- Critical
- Pilar de Zero Trust
- Identity (peso 3)
- Fixtures de referencia
- 3
- Cobertura de ramas
- Observada: los fixtures prueban los veredictos que ejercitan
- Procedencia
- baseline
Qué comprueba
Legacy authentication protocols such as IMAP, POP3, SMTP, and ActiveSync do not support modern authentication or MFA, making them a primary attack vector for password spray and brute-force attacks. Blocking legacy authentication through Conditional Access is essential to prevent these protocols from bypassing MFA controls.
Valor recomendado
All legacy authentication protocols blocked via Conditional Access for all users
Remediación
Create a Conditional Access policy targeting all users and all cloud applications with the client apps condition set to Exchange ActiveSync clients and other clients, then set the grant control to block access. Verify the policy is in enabled state and monitor sign-in logs for any remaining legacy authentication attempts. Coordinate with application owners to migrate any remaining legacy protocol dependencies to modern authentication.
Veredictos probados con fixtures
Cada veredicto de esta tabla está probado por un fixture de referencia en la suite de pruebas que valida el módulo. La tabla se deriva de la última ejecución en verde; no puede editarse a mano.
| Escenario | Veredicto esperado |
|---|---|
| clean | PASS |
| known-bad | FAIL |
| throttled | Not Assessed |
Mapeos a marcos de referencia
- CISA SCuBA
- MS.AAD.1.1v1
- NIST SP 800-53
- IA-2, AC-17(2)
- CIS M365 Benchmark
- 5.2.2.3
- MITRE ATT&CK
- T1078, T1110.001