9.7 Ensure that 'PHP version' is currently supported (if in use)

Information

Periodically, older versions of PHP may be deprecated and no longer supported. Using a supported version of PHP for app services is recommended to avoid potential unpatched vulnerabilities.

Rationale:

Deprecated and unsupported versions of programming and scripting languages can present vulnerabilities which may not be addressed or may not be addressable.

Impact:

If your app is written using version-dependent features or libraries, they may not be available on more recent versions. If you wish to update, research the impact thoroughly.

NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.

Solution

Remediate from Azure Portal

From Azure Home open the Portal Menu in the top left

Go to App Services

Click on each App

Under Settings section, click on Configuration

Click on the General settings pane, ensure that for a Stack of PHP the Major Version and Minor Version reflect a currently supported release.

NOTE: No action is required If PHP version is set to Off or is set with an empty value as PHP is not used by your app.

Remediate from Azure CLI
List the available PHP runtimes:

az webapp list-runtimes

To set a currently supported PHP version for an existing app, run the following command:

az webapp config set --resource-group <RESOURCE_GROUP_NAME> --name <APP_NAME> [--linux-fx-version <PHP_RUNTIME_VERSION>][--php-version <PHP_VERSION>]

Remediate from PowerShell
To set a currently supported PHP version for an existing app, run the following command:

Set-AzWebApp -ResourceGroupName <RESOURCE_GROUP_NAME> -Name <APP_NAME> -phpVersion <PHP_VERSION>

NOTE: Currently there is no way to update an existing web app Linux FX Version setting using PowerShell, nor is there a way to create a new web app using PowerShell that configures the PHP runtime in the Linux FX Version setting.

Default Value:

The version of PHP is whatever was selected upon App creation.

See Also

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

Item Details

Category: SYSTEM AND SERVICES ACQUISITION

References: 800-53|SA-22, CSCv7|2.2

Plugin: microsoft_azure

Control ID: 28ce0f4a3ec1b70cac83ebe079cdee415d158948e0287288a5ea22ae1f986b55