Authorization and security: RBAC, Zero Trust, defense in depth, and Defender for Cloud¶
After authentication verifies identity, authorization and security controls determine permissions, risk posture, and threat protection.
Azure RBAC¶
Azure role-based access control (RBAC) authorizes who can perform which actions on which resources at which scope.
RBAC building blocks:
| Building block | Purpose |
|---|---|
| Security principal | User, group, service principal, or managed identity |
| Role definition | Collection of permissions, such as Reader or Contributor |
| Scope | Management group, subscription, resource group, or resource |
| Role assignment | Grants a role to a principal at a scope |
Exam rule: who can perform an action at a scope → Azure RBAC.
RBAC is about authorization, not authentication. A user may authenticate successfully but still be denied if no role assignment grants the action.
Common built-in roles at AZ-900 level:
- Owner: full access including permission to grant access to others;
- Contributor: manage resources but not grant access;
- Reader: view resources without making changes.
Zero Trust¶
Zero Trust assumes breach is possible and verifies explicitly rather than trusting by network location alone.
Core principles:
- verify explicitly;
- use least privilege access;
- assume breach and limit blast radius.
Exam clue: never trust, always verify, least privilege, identity-centric security → Zero Trust.
Defense in depth¶
Defense in depth uses multiple layers of security so one failure does not expose everything.
Example layers:
Identity and access control
└── Perimeter and network controls
└── Compute and application security
└── Data protection and encryption
└── Monitoring and response
If one layer fails, others still provide protection.
Exam clue: multiple overlapping security layers → defense in depth.
Microsoft Defender for Cloud¶
Defender for Cloud is a cloud security posture management and threat protection service for Azure and hybrid workloads.
It helps with:
- secure score and recommendations;
- regulatory compliance dashboards;
- threat detection for servers, databases, storage, and other resources on supported plans.
Exam clue: security recommendations, posture management, and threat protection across Azure resources → Microsoft Defender for Cloud.
Defender for Cloud complements RBAC and network controls; it does not replace them.
Scenario¶
A developer should view production resources but must not change them or assign access.
Best fit: Reader role assignment at the appropriate scope.
Scenario¶
Security leadership wants continuous recommendations to improve configuration and detect suspicious activity in Azure subscriptions.
Best fit: Microsoft Defender for Cloud.
Exam clues¶
- Permission to create VMs in one resource group → RBAC role assignment.
- Layered security controls → defense in depth.
- Verify every access attempt, least privilege → Zero Trust.
- Posture and threat protection service → Defender for Cloud.
Check yourself¶
Statement: RBAC determines whether a password is valid.
Answer: False. Authentication verifies identity; RBAC authorizes actions after identity is established.