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

From 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 the Select apps radio button is selected.
11. Under Select, ensure Microsoft Admin Portals is listed.

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://docs.microsoft.com/en-us/azure/active-directory/conditional-access/concept-conditional-access-users-groups
3. https://learn.microsoft.com/en-us/entra/identity/conditional-access/how-to-policy-mfa-admin-portals

Additional Information

These policies should be tested by using the What If tool in the References. Setting these can and will create issues with administrators changing settings until they use an MFA device linked to their accounts. An emergency access account is recommended for this eventuality if all administrators are locked out. Please see the documentation in the references for further information. Similarly further testing can also be done via the insights and reporting resource in References which monitors Azure sign ins.