azureazure-active-directorymicrosoft-entra-id

Entra ID OIDC Failed Auth Attempt Logs


I have an Azure Entra ID OIDC app. It's configured with a client secret for machine-to-machine auth using grant_type=client_credentials.

I would like to find logs in Azure for failed OIDC login attempts (e.g. requests to https://login.microsoftonline.com/mytenant/oauth2/token that have the wrong client_id field). Note that I want to see logs for all failed attempts to my tenant, not just logs for attempts that have valid client_id fields.

I cannot seem to find such logs for failed OIDC token attempts anywhere in the console. The Sign-In Logs doesn't show any failed attempts, nor does the Audit Logs section under Entra ID (even after I made several failed attempts myself).

Where can I find these logs?


Solution

  • Note: Invalid client_id failures do not appear in the Azure AD Sign-In Logs because these requests are often rejected at the point of client ID validation, before the system even attempts to authenticate.

    For sample, If the client_id is valid but the client_secret is incorrect, the request proceeds further in the authentication flow (after validating the client_id), and the failure is logged in the Sign-In Logs with an error like invalid_client_secret.

    Hence Azure AD will not log invalid client_id failures explicitly, as it is considered an error that occurs before authentication actually takes place.

    I tried to generate access token by passing the wrong client secret:

    https://login.microsoftonline.com/TenantID/oauth2/v2.0/token
    
    grant_type : client_credentials
    client_id : ClientID
    client_secret : Secret
    scope : https://graph.microsoft.com/.default
    

    enter image description here

    This invalid secret failure log is captured under the Sign-in logs of Service principal sign-ins:

    enter image description here

    But Now I tried to pass the invalid client ID, there is no log captured:

    enter image description here

    enter image description here