cis-azure-foundations-5-2-4

name	cis-azure-foundations-5.2.4
description	Ensure a multifactor authentication policy exists for all users
category	cis-azure-foundations
version	5.0.0
author	cyberstrike-official
tags	["cis","azure","identity","conditional-access"]
cis_id	5.2.4
cis_benchmark	CIS Microsoft Azure Foundations Benchmark v5.0.0
tech_stack	["azure"]
cwe_ids	[]
chains_with	["cis-azure-foundations-5.2.5","cis-azure-foundations-5.2.6"]
prerequisites	[]
severity_boost	{}

Ensure a multifactor authentication policy exists for all users

Description

A Conditional Access policy can be enabled to ensure that users are required to use Multifactor Authentication (MFA) to login.

Note: Since 2024, Azure has been rolling out mandatory multifactor authentication. For more information:

• https://azure.microsoft.com/en-us/blog/announcing-mandatory-multi-factor-authentication-for-azure-sign-in
• https://learn.microsoft.com/en-us/entra/identity/authentication/concept-mandatory-multifactor-authentication

Rationale

Multifactor authentication is strongly recommended to increase the confidence that a claimed identity can be proven to be the subject of the identity. This results in a stronger authentication chain and reduced likelihood of exploitation.

Impact

There is an increased cost associated with Conditional Access policies because of the requirement of Microsoft Entra ID P1 or P2 licenses. Additional support overhead may also need to be considered.

Audit Procedure

Using Azure Portal

1. From Azure Home open the Portal Menu in the top left, and select Microsoft Entra ID.
2. Scroll down in the menu on the left, and select Security.
3. Select on the left side Conditional Access.
4. Select Policies.
5. Select the policy you wish to audit.
6. Click the blue text under Users.
7. Under Include ensure that All Users is specified.
8. Under Exclude ensure that no users or groups are specified. If there are users or groups specified for exclusion, a very strong justification should exist for each exception, and all excepted account-level objects should be recorded in documentation along with the justification for comparison in future audits.

Expected Result

A Conditional Access policy should exist that requires MFA for all users, targeting all cloud apps, with the Grant control set to Require multifactor authentication.

Remediation

Remediate from Azure Portal

1. From Azure Home open Portal menu in the top left, and select Microsoft Entra ID.
2. Select Security.