9.4 Ensure Web App is using the latest version of TLS encryption

Information

The TLS (Transport Layer Security) protocol secures transmission of data over the internet using standard encryption technology. Encryption should be set with the latest version of TLS. App service allows TLS 1.2 by default, which is the recommended TLS level by industry standards such as PCI DSS.

Rationale:

App service currently allows the web app to set TLS versions 1.0, 1.1 and 1.2. It is highly recommended to use the latest TLS 1.2 version for web app secure connections.

Solution

Remediate from Azure Portal

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

Go to App Services

Click on each App

Under Setting section, Click on SSL settings

Under the Bindings pane, set Minimum TLS Version to 1.2 under Protocol Settings section

Remediate from Azure CLI
To set TLS Version for an existing app, run the following command:

az webapp config set --resource-group <RESOURCE_GROUP_NAME> --name <APP_NAME> --min-tls-version 1.2

Remediate from PowerShell

Set-AzWebApp -ResourceGroupName <RESOURCE_GROUP_NAME> -Name <APP_NAME> -MinTlsVersion 1.2

Default Value:

By default, TLS Version feature will be set to 1.2 when a new app is created using the command-line tool or Azure Portal console.

See Also

https://workbench.cisecurity.org/benchmarks/16820

Item Details

Category: ACCESS CONTROL, IDENTIFICATION AND AUTHENTICATION, SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|AC-17(2), 800-53|IA-5, 800-53|IA-5(1), 800-53|SC-8, 800-53|SC-8(1), CSCv7|14.4

Plugin: microsoft_azure

Control ID: 448db334dc5dc2bb8239101de7cfcd5155090c90e43572fd3d34cba8a2576c59