cis-azure-compute-2-1-4

name	cis-azure-compute-2.1.4
description	Ensure 'Basic Authentication Publishing Credentials' are 'Disabled'
category	cis-azure-compute
version	2.0.0
author	cyberstrike-official
tags	["cis","azure","app-service","authentication","basic-auth","publishing-credentials","identity"]
cis_id	2.1.4
cis_benchmark	CIS Microsoft Azure Compute Services Benchmark v2.0.0
tech_stack	["azure"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

Ensure 'Basic Authentication Publishing Credentials' are 'Disabled'

Description

Basic Authentication Publishing Credentials provides the ability to publish -- or deploy to -- an App Service app without a centralized Identity Provider. For a more effective, capable, and secure solution for Identity, Authentication, Authorization, and Accountability, a centralized Identity Provider such as Entra ID is strongly advised.

Rationale

Basic Authentication introduces an identity silo for privileged access to a resource and produces logging which may not provide a full chain of accountability. This can be exploited in numerous ways and represents a significant vulnerability and attack vector.

Impact

Disabling 'Basic Auth Publishing Credentials' will prevent the following deployment methods from working:

FTP Basic Auth Publishing Credentials:

• FTP
• FTPS

SCM Basic Auth Publishing Credentials:

• Local Git
• GitHub
• Azure Repos
• Bitbucket
• Visual Studio (Version 17.12 and earlier)

If this recommendation cannot be implemented because one of the above listed deployment methods is necessary and cannot be adapted, compensating controls (e.g. using FTPS Only and disabling only "SCM Basic Auth Publishing Credentials") are recommended to reduce potential attack surface.

An Identity Provider that can be used by the App Service app for authenticating users is required.

Audit Procedure

Using Azure Portal

1. Search for, and open App Services from the search bar.
2. For each App Service listed:
3. Click on the App Service name.
4. Under the Settings menu item, click on Configuration
5. Under the General settings tab, scroll down to locate the two Basic Auth settings:
   • SCM Basic Auth Publishing Credentials
   • FTP Basic Auth Publishing Credentials

Both radio buttons should indicate a status of Off. Repeat this procedure for each App Service.

Using Azure CLI

Run the following command to list apps:

az webapp list

For each app, run the following command to get the basic authentication for FTP setting:

az resource show --resource-group <resource-group-name> --name ftp --namespace Microsoft.Web --resource-type basicPublishingCredentialsPolicies --parent sites/<app-name> --query properties.allow