9.4 Ensure the web app has 'Client Certificates (Incoming client certificates)' set to 'On'

Information

Client certificates allow for the app to request a certificate for incoming requests. Only clients that have a valid certificate will be able to reach the app.

Rationale:

The TLS mutual authentication technique in enterprise environments ensures the authenticity of clients to the server. If incoming client certificates are enabled, then only an authenticated client who has valid certificates can access the app.

Impact:

Utilizing and maintaining client certificates will require additional work to obtain and managed replacement and key rotation.

Solution

From Azure Console

Login to Azure Portal using https://portal.azure.com

Go to App Services

Click on each App

Under Setting section, Click on Configuration

Set the option Client certificate mode located under Incoming client certificates is set to Require

Using Azure Command Line Interface
To set Incoming client certificates value for an existing app, run the following command:

az webapp update --resource-group <RESOURCE_GROUP_NAME> --name <APP_NAME> --set clientCertEnabled=true

Default Value:

By default, incoming client certificates will be disabled when a new app is created using the command-line tool or Azure Portal console.

See Also

https://workbench.cisecurity.org/files/3459

Item Details

Category: ACCESS CONTROL, MEDIA PROTECTION

References: 800-53|AC-3, 800-53|MP-2, CSCv7|14

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