Azure role-based access control (Azure RBAC) vs. access policies (legacy)
Important
When using the Access Policy permission model, a user with the Contributor, Key Vault Contributor, or any other role that includes Microsoft.KeyVault/vaults/write permissions for the key vault management plane can grant themselves data plane access by setting a Key Vault access policy. To prevent unauthorized access and management of your key vaults, keys, secrets, and certificates, it's essential to limit Contributor role access to key vaults under the Access Policy permission model. To mitigate this risk, we recommend you use the Role-Based Access Control (RBAC) permission model, which restricts permission management to the 'Owner' and 'User Access Administrator' roles, allowing a clear separation between security operations and administrative duties. See the Key Vault RBAC Guide and What is Azure RBAC? for more information.
Azure Key Vault offers two authorization systems: Azure role-based access control (Azure RBAC), which operates on Azure's control and data planes, and the access policy model, which operates on the data plane alone.
Azure RBAC is built on Azure Resource Manager and provides centralized access management of Azure resources. With Azure RBAC you control access to resources by creating role assignments, which consist of three elements: a security principal, a role definition (predefined set of permissions), and a scope (group of resources or individual resource).
The access policy model is a legacy authorization system, native to Key Vault, which provides access to keys, secrets, and certificates. You can control access by assigning individual permissions to security principals (users, groups, service principals, and managed identities) at Key Vault scope.
Data plane access control recommendation
Azure RBAC is the recommended authorization system for the Azure Key Vault data plane. It offers several advantages over Key Vault access policies:
- Azure RBAC provides a unified access control model for Azure resources — the same APIs are used across all Azure services.
- Access management is centralized, providing administrators with a consistent view of access granted to Azure resources.
- The right to grant access to keys, secrets, and certificates is better controlled, requiring Owner or User Access Administrator role membership.
- Azure RBAC is integrated with Privileged Identity Management, ensuring that privileged access rights are time-limited and expire automatically.
- Security principals' access can be excluded at given scope(s) through the use of Deny assignments.
To transition your Key Vault data plane access control from access policies to RBAC, see Migrate from vault access policy to an Azure role-based access control permission model.