Cis Azure Foundations 5.2.7

Ensure multifactor authentication is required to access Microsoft Admin Portals

Description

This recommendation ensures that users accessing Microsoft Admin Portals (i.e. Microsoft 365 Admin, Microsoft 365 Defender, Exchange Admin Center, Azure Portal, etc.) are required to use multi-factor authentication (MFA) credentials when logging into an Admin Portal.

Rationale

Administrative Portals for Microsoft Azure should be secured with a higher level of scrutiny to authenticating mechanisms. Enabling multi-factor authentication is recommended to reduce the potential for abuse of Administrative actions, and to prevent intruders or compromised admin credentials from changing administrative settings.

IMPORTANT: While this recommendation allows exceptions to specific Users or Groups, they should be very carefully tracked and reviewed for necessity on a regular interval through an Access Review process. It is important that this rule be built to include "All Users" to ensure that all users not specifically excepted will be required to use MFA to access Admin Portals.

Impact

Conditional Access policies require Microsoft Entra ID P1 or P2 licenses. Similarly, they may require additional overhead to maintain if users lose access to their MFA. Any users or groups which are granted an exception to this policy should be carefully tracked, be granted only minimal necessary privileges, and conditional access exceptions should be reviewed or investigated.

Audit Procedure

Using Azure Portal

1. From the Azure Admin Portal dashboard, open Microsoft Entra ID.
2. In the menu on the left of the Entra ID blade, click Security.
3. In the menu on the left of the Security blade, click Conditional Access.
4. In the menu on the left of the Conditional Access blade, click Policies.
5. Click on the name of the policy you wish to audit.
6. Click the blue text under Users.
7. Under the Include section of Users, review Users and Groups to ensure that All Users is selected.
8. Under the Exclude section of Users, review the Users and Groups that are excluded from the policy (NOTE: this should be limited to break-glass emergency access accounts, non-interactive service accounts, and other carefully considered exceptions).
9. On the left side, click the blue text under Target Resources.
10. Under the Include section of Target resources, ensure that the Select apps radio button is selected.
11. Under Select, ensure Microsoft Admin Portals is listed.

Expected Result

A Conditional Access policy should exist requiring MFA for all users accessing Microsoft Admin Portals, with only break-glass emergency access accounts and non-interactive service accounts excluded.

Remediation

Remediate from Azure Portal

1. From the Azure Admin Portal dashboard, open Microsoft Entra ID.
2. Click Security in the Entra ID blade.
3. Click Conditional Access in the Security blade.
4. Click Policies in the Conditional Access blade.
5. Click + New policy.
6. Enter a name for the policy.
7. Click the blue text under Users.
8. Under Include, select All users.
9. Under Exclude, check Users and groups.
10. Select users or groups to be exempted from this policy (e.g. break-glass emergency accounts, and non-interactive service accounts) then click the Select button.
11. Click the blue text under Target resources.
12. Under Include, click the Select apps radio button.
13. Click the blue text under Select.
14. Check the box next to Microsoft Admin Portals then click the Select button.
15. Click the blue text under Grant.
16. Under Grant access check the box for Require multi-factor authentication then click the Select button.
17. Before creating, set Enable policy to Report-only.
18. Click Create.

After testing the policy in report-only mode, update the Enable policy setting from Report-only to On.

Default Value

MFA is not enabled by default for administrative actions.

References

1. https://learn.microsoft.com/en-us/security/benchmark/azure/mcsb-identity-management#im-7-restrict-resource-access-based-on--conditions
2. https://learn.microsoft.com/en-us/entra/identity/conditional-access/concept-conditional-access-users-groups
3. https://learn.microsoft.com/en-us/entra/identity/conditional-access/policy-old-require-mfa-admin-portals

CIS Controls

Profile

Level 2 | Manual