Azure Authentication in Prowler¶

Prowler for Azure supports multiple authentication types. Authentication methods vary between Prowler App and Prowler CLI:

Prowler App:

Service Principal Application

Prowler CLI:

Service Principal Application (Recommended)
AZ CLI credentials
Interactive browser authentication
Managed Identity Authentication

Required Permissions¶

Prowler for Azure requires two types of permission scopes:

Microsoft Entra ID Permissions¶

These permissions allow Prowler to retrieve metadata from the assumed identity and perform specific Entra checks. While not mandatory for execution, they enhance functionality.

Assigning Required API Permissions¶

Assign the following Microsoft Graph permissions:

Directory.Read.All
Policy.Read.All
UserAuthenticationMethod.Read.All (optional, for multifactor authentication (MFA) checks)

Note

Replace Directory.Read.All with Domain.Read.All for more restrictive permissions. Note that Entra checks related to DirectoryRoles and GetUsers will not run with this permission.

Azure PortalAzure CLI

Go to your App Registration > "API permissions"
Click "+ Add a permission" > "Microsoft Graph" > "Application permissions"
Search and select:
- Directory.Read.All
- Policy.Read.All
- UserAuthenticationMethod.Read.All
Click "Add permissions", then grant admin consent

To grant permissions to a Service Principal, execute the following command in a terminal:

az ad app permission add --id {appId} --api 00000003-0000-0000-c000-000000000000 --api-permissions 7ab1d382-f21e-4acd-a863-ba3e13f7da61=Role 246dd0d5-5bd0-4def-940b-0421030a5b68=Role 38d9df27-64da-44fd-b7c5-a6fbac20248f=Role

Once the permissions are assigned, admin consent is required to finalize the changes. An administrator should run:
```
az ad app permission admin-consent --id {appId}
```

Subscription Scope Permissions¶

These permissions are required to perform security checks against Azure resources. The following RBAC roles must be assigned per subscription to the entity used by Prowler:

Reader – Grants read-only access to Azure resources.
ProwlerRole – A custom role with minimal permissions needed for some specific checks, defined in the prowler-azure-custom-role.

Assigning "Reader" Role at the Subscription Level¶

By default, Prowler scans all accessible subscriptions. If you need to audit specific subscriptions, you must assign the necessary role Reader for each one. For streamlined and less repetitive role assignments in multi-subscription environments, refer to the following section.

Azure PortalAzure CLI

To grant Prowler access to scan a specific Azure subscription, follow these steps in Azure Portal: Navigate to the subscription you want to audit with Prowler.
In the left menu, select “Access control (IAM)”.
Click “+ Add” and select “Add role assignment”.
In the search bar, enter Reader, select it and click “Next”.
In the “Members” tab, click “+ Select members”, then add the accounts to assign this role.
Click “Review + assign” to finalize and apply the role assignment.

Adding the Reader Role to a Subscription

Open a terminal and execute the following command to assign the Reader role to the identity that is going to be assumed by Prowler:

az role assignment create --role "Reader" --assignee <user, group, or service principal> --scope /subscriptions/<subscription-id>

If the command is executed successfully, the output is going to be similar to the following:

{
    "condition": null,
    "conditionVersion": null,
    "createdBy": "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
    "createdOn": "YYYY-MM-DDTHH:MM:SS.SSSSSS+00:00",
    "delegatedManagedIdentityResourceId": null,
    "description": null,
    "id": "/subscriptions/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX/providers/Microsoft.Authorization/roleAssignments/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
    "name": "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
    "principalId": "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
    "principalName": "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
    "principalType": "ServicePrincipal",
    "roleDefinitionId": "/subscriptions/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX/providers/Microsoft.Authorization/roleDefinitions/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
    "roleDefinitionName": "Reader",
    "scope": "/subscriptions/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
    "type": "Microsoft.Authorization/roleAssignments",
    "updatedBy": "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
    "updatedOn": "YYYY-MM-DDTHH:MM:SS.SSSSSS+00:00"
}

Assigning "ProwlerRole" Permissions at the Subscription Level¶

Some read-only permissions required for specific security checks are not included in the built-in Reader role. To support these checks, Prowler utilizes a custom role, defined in prowler-azure-custom-role. Once created, this role can be assigned following the same process as the Reader role.

The checks requiring this ProwlerRole can be found in this section.

Azure PortalAzure CLI

Download the Prowler Azure Custom Role
Modify assignableScopes to match your Subscription ID (e.g. /subscriptions/xxxx-xxxx-xxxx-xxxx)
Go to your Azure Subscription > "Access control (IAM)"
Click "+ Add" > "Add custom role", choose "Start from JSON" and upload the modified file
Click "Review + Create" to finish
Return to "Access control (IAM)" > "+ Add" > "Add role assignment"
- Assign the Reader role to the Application created in the previous step
- Then repeat the same process assigning the custom ProwlerRole

Note

The assignableScopes field in the JSON custom role file must be updated to reflect the correct subscription or management group. Use one of the following formats: /subscriptions/<subscription-id> or /providers/Microsoft.Management/managementGroups/<management-group-id>.

To create a new custom role, open a terminal and execute the following command:

az role definition create --role-definition '{                                                                                                                   640ms  lun 16 dic 17:04:17 2024
                    "Name": "ProwlerRole",
                    "IsCustom": true,
                    "Description": "Role used for checks that require read-only access to Azure resources and are not covered by the Reader role.",
                    "AssignableScopes": [
                    "/subscriptions/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX" // USE YOUR SUBSCRIPTION ID
                    ],
                    "Actions": [
                    "Microsoft.Web/sites/host/listkeys/action",
                    "Microsoft.Web/sites/config/list/Action"
                    ]
                }'

If the command is executed successfully, the output is going to be similar to the following:

{
    "assignableScopes": [
        "/subscriptions/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"
    ],
    "createdBy": null,
    "createdOn": "YYYY-MM-DDTHH:MM:SS.SSSSSS+00:00",
    "description": "Role used for checks that require read-only access to Azure resources and are not covered by the Reader role.",
    "id": "/subscriptions/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX/providers/Microsoft.Authorization/roleDefinitions/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
    "name": "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
    "permissions": [
        {
            "actions": [
                "Microsoft.Web/sites/host/listkeys/action",
                "Microsoft.Web/sites/config/list/Action"
            ],
            "condition": null,
            "conditionVersion": null,
            "dataActions": [],
            "notActions": [],
            "notDataActions": []
        }
    ],
    "roleName": "ProwlerRole",
    "roleType": "CustomRole",
    "type": "Microsoft.Authorization/roleDefinitions",
    "updatedBy": "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX",
    "updatedOn": "YYYY-MM-DDTHH:MM:SS.SSSSSS+00:00"
}

Additional Resources¶

For more detailed guidance on subscription management and permissions:

Warning

Some permissions in ProwlerRole involve write access. If a ReadOnly lock is attached to certain resources, you may encounter errors, and findings for those checks will not be available.

Checks Requiring `ProwlerRole`¶

The following security checks require the ProwlerRole permissions for execution. Ensure the role is assigned to the identity assumed by Prowler before running these checks:

app_function_access_keys_configured
app_function_ftps_deployment_disabled

Service Principal Application Authentication (Recommended)¶

This method is required for Prowler App and recommended for Prowler CLI.

Creating the Service Principal¶

For more information, see Creating Prowler Service Principal.

Environment Variables (CLI)¶

For Prowler CLI, set up the following environment variables:

export AZURE_CLIENT_ID="XXXXXXXXX"
export AZURE_TENANT_ID="XXXXXXXXX"
export AZURE_CLIENT_SECRET="XXXXXXX"

Execution with the --sp-env-auth flag fails if these variables are not set or exported.

AZ CLI Authentication¶

Available only for Prowler CLI

Use stored Azure CLI credentials:

prowler azure --az-cli-auth

Managed Identity Authentication¶

Available only for Prowler CLI

Authenticate via Azure Managed Identity (when running on Azure resources):

prowler azure --managed-identity-auth

Browser Authentication¶

Available only for Prowler CLI

Authenticate using the default browser:

prowler azure --browser-auth --tenant-id <tenant-id>

Note: The tenant-id parameter is mandatory for browser authentication.

Azure Authentication in Prowler¶

Required Permissions¶

Microsoft Entra ID Permissions¶

Assigning Required API Permissions¶

Subscription Scope Permissions¶

Assigning "Reader" Role at the Subscription Level¶

Assigning "ProwlerRole" Permissions at the Subscription Level¶

Additional Resources¶

Checks Requiring ProwlerRole¶

Service Principal Application Authentication (Recommended)¶

Creating the Service Principal¶

Environment Variables (CLI)¶

AZ CLI Authentication¶

Managed Identity Authentication¶

Browser Authentication¶

Checks Requiring `ProwlerRole`¶