MSGraph Multi-Factor Authentication "interaction_required" - authentication

Question

I'm using the Microsoft Graph login endpoint: login.microsoftonline.com/[tenantId]/oauth2/token with a grant type of "password" to log users in:
{
"grant_type": "password",
"client_id": "xxx",
"client_secret": "xxx",
"scope": "openid",
"resource": "https://graph.microsoft.com",
"username": "username",
"password": "********",
}
When I post this with users that are not enrolled in multi-factor authentication on our AD I get back the expected results including an access_token and refresh_token
However on users that are enrolled I get back a HttpStatusCode.BadRequest with an error of "interaction_required"
According to documentation from Microsoft found here:
In this case, your app receives a 400 with an interaction_required
error during access token acquisition or a 403 with
insufficient_claims error when calling Microsoft Graph. In both cases,
the error response contains additional information that can be
presented to the authorize endpoint to challenge the user for
additional information (like multi-factor authentication or device
enrollment).
However I do not see any additional information in the results and can't find much information on next steps. The JSON I get back looks like this:
{
"error":"interaction_required",
"error_description":"AADSTS50079: Due to a configuration change made by your administrator, or because you moved to a new location, you must enroll in multi-factor authentication to access '00000003-0000-0000-c000-000000000000'.\r\nTrace ID: aee10c85-fd12-42ec-be6c-76d546500100\r\nCorrelation ID: 0ee3ebac-f702-4fbc-be76-fd6a291ad488\r\nTimestamp: 2021-09-09 17:45:24Z",
"error_codes":[50079],"timestamp":"2021-09-09 17:45:24Z",
"trace_id":"aee10c85-fd12-42ec-be6c-76d546500100",
"correlation_id":"0ee3ebac-f702-4fbc-be76-fd6a291ad488",
"error_uri":"https://login.microsoftonline.com/error?code=50079",
"suberror":"basic_action"
}
But I am getting back "interaction_required" and confirmed with our AD administrator that they are definitely enrolled. So I am at a bit of a loss for next steps to resolve this.

Answer 1

Cause :User is attempting a authentication method that requires Multi-factor authentication
Try to catch the error you get, and perform a new request according to steps for your flow scenarios by referring from this MS docs
Microsoft Graph has special considerations when building apps in
Conditional Access environments. Since Conditional Access policies are
assigned the specific datasets, Azure AD will enforce Conditional
Access policies based on the data behind Graph - rather than Graph
itself.
(or check below points)
Conditional access policies prevent non-interactive flows to work.
Possible solutions...
Use a interactive flow instead.
If you are using a interactive flow and still getting this error, please make sure openid is one of the scopes during the interactive sign-in. You might be getting the error after the interactive sign-in and trying to exchange the authorization code for a access token...
Example:
https://login.microsoftonline.com/contoso.onmicrosoft.com/oauth2/authorize?client_id=#...#
&response_type=code
&scope=openid groups.read.all
&nonce=1234
&redirect_uri=https://app.contoso.com
Notice "scope=openid groups.read.all" in the request above
Add the client application to the exception list of the Conditional Access Policy
Add the user to the exception list of the Conditional Access Policy
If you are not using conditional access policies and the user is directly enabled for MFA, then as a last thing, disable MFA for the user if solutions above do not work for you.
Or you can use certificate based authentication instead of MFA
References:
login-to-azure-web-application-fails-with-aadsts50079
SO thread