Cis Azure Compute 2.4.11

---
name: cis-azure-compute-2.4.11
description: "Ensure managed identities are configured"
category: cis-azure-compute
version: "2.0.0"
author: cyberstrike-official
tags: [cis, azure, functions, deployment-slots]
cis_id: "2.4.11"
cis_benchmark: "CIS Microsoft Azure Compute Services Benchmark v2.0.0"
tech_stack: [azure]
cwe_ids: []
chains_with: []
prerequisites: []
severity_boost: {}
---

# Ensure managed identities are configured

## Description

Managed identities from Microsoft Entra ID allow function app deployment slots to securely access other Azure services without the need to provision or rotate any secrets.

This recommendation applies to function apps using the Consumption, Premium, or Dedicated (App Service) plans, which support deployment slots.

## Rationale

Using managed identities with function app deployment slots eliminates the need to store and manage credentials to access Azure resources.

## Impact

Minor administrative overhead to configure and manage role assignments for managed identities.

## Audit Procedure

### Using Azure Portal

1. Go to `App Services` or `Function App`.
2. Click the name of a function app.
3. Under `Deployment`, click `Deployment slots`.
4. Click the name of a deployment slot.
5. Under `Settings`, click `Identity`.
6. Ensure that in the `System assigned` pane, the `Status` is set to `On`, and an `Object (principal) ID` is displayed, or that in the `User assigned` pane, a managed identity is listed.
7. Repeat steps 1-6 for each function app and deployment slot.

### Using Azure CLI

Run the following command to list function apps:

```bash
az functionapp list
```

For each function app, run the following command to list deployment slots:

```bash
az functionapp deployment slot list --resource-group <resource-group-name> --name <function-app-name>
```

For each deployment slot, ensure that `identity` contains `type` set to `SystemAssigned`, `UserAssigned`, or both.

## Expected Result

The deployment slot should have a managed identity configured, either system-assigned, user-assigned, or both.

## Remediation

### Using Azure Portal

1. Go to `App Services` or `Function App`.
2. Click the name of a function app.
3. Under `Deployment`, click `Deployment slots`.
4. Click the name of a deployment slot.
5. Under `Settings`, click `Identity`.
6. To add a system assigned managed identity:
   1. In the `System assigned` pane, under `Status`, click `On`.
   2. Click `Save`.
   3. Click `Yes`.
7. To add a user assigned managed identity:
   1. In the `User assigned` pane, click `Add`.
   2. Use the filter box to search for a managed identity.
   3. Select the identity.
   4. Click `Add`.
8. Repeat steps 1-7 for each function app and deployment slot requiring remediation.

### Using Azure PowerShell

For each deployment slot requiring remediation, run the following command to assign a system-assigned managed identity:

```powershell
Set-AzWebAppSlot -ResourceGroupName <resource-group-name> -Name <function-app-name> -Slot <deployment-slot-name> -AssignIdentity $true
```

## Default Value

Managed identities are disabled by default for function app deployment slots.

## References

1. https://learn.microsoft.com/en-us/security/benchmark/azure/mcsb-identity-management#im-1-use-centralized-identity-and-authentication-system
2. https://learn.microsoft.com/en-us/azure/app-service/overview-managed-identity
3. https://learn.microsoft.com/en-us/cli/azure/functionapp
4. https://learn.microsoft.com/en-us/powershell/module/az.websites/set-azwebappslot

## Profile

Level 1 | Automated