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

Overview

Periodically, newer versions are released for Python software either due to security flaws or to include additional functionality. Using the latest Python version for web apps is recommended in order to take advantage of security fixes, if any, and/or new functionalities of the newer version.

Rationale

Newer versions may contain security enhancements and additional functionality. Using the latest version is recommended in order to take advantage of enhancements and new capabilities. With each software installation, organizations need to determine if a given update meets their requirements. They must also verify the compatibility and support provided for any additional software against the update revision that is selected.

Impact

If your app is written using version-dependent features or libraries, they may not be available on the latest version. If you wish to upgrade, research the impact thoroughly. Upgrading may have unforeseen consequences that could result in downtime.

Default value

You have to select a version during app creation.

Remediation guidance

From Azure Console

Open the web app using the Open in Azure button.
Select Configuration
Go to General settings
Under the Stack settings, for Python, select for Major version and Minor version the latest stable and supported release

Using Azure Command Line Interface

To see the list of supported runtimes:

az webapp list-runtimes

To set the latest Python version for an existing app, run the following command:

az webapp config set --resource-group <resourceGroup> --name <applicationName> [--linux-fx-version <pythonRuntimeVersion>] [--windows-fx-version <pythonRuntimeVersion>]

Multiple Remediation Paths

Azure

SERVICE-WIDE (RECOMMENDED when many resources are affected): Assign Azure Policy initiatives at management group/subscription scope and trigger remediation tasks.

az policy assignment create --name <assignment-name> --scope /subscriptions/<subscription-id> --policy-set-definition <initiative-id>
az policy remediation create --name <remediation-name> --policy-assignment <assignment-id>

ASSET-LEVEL: Apply the resource-specific remediation steps above to the listed non-compliant resources.

PREVENTIVE: Embed Azure Policy checks into landing zones and IaC workflows to block or auto-remediate drift.

References for Service-Wide Patterns

Azure Policy overview: https://learn.microsoft.com/en-us/azure/governance/policy/overview
Azure Policy remediation: https://learn.microsoft.com/en-us/azure/governance/policy/how-to/remediate-resources
Azure Policy initiative structure: https://learn.microsoft.com/en-us/azure/governance/policy/concepts/initiative-definition-structure

Operational Rollout Workflow

Use this sequence to reduce risk and avoid repeated drift.

1. Contain at Service-Wide Scope First (Recommended)

Azure: assign policy initiatives at management group/subscription scope and run remediation tasks.

az policy assignment create --name <assignment-name> --scope /subscriptions/<subscription-id> --policy-set-definition <initiative-id>
az policy remediation create --name <remediation-name> --policy-assignment <assignment-id>

2. Remediate Existing Affected Assets

Execute the control-specific Console/CLI steps documented above for each flagged resource.
Prioritize internet-exposed and production assets first.

3. Validate and Prevent Recurrence

Re-scan after each remediation batch.
Track exceptions with owner and expiry date.
Add preventive checks in IaC/CI pipelines.

Query logic

These are the stored checks tied to this control.

Azure app services running unsupported Python versions

Connectors

Microsoft Azure

Covered asset types

Site

Expected check: eq []

{
  sites(
    where: { siteConfig: { NOT: { pythonVersion: "" }, isDeprecated: true } }
  ) {
    ...AssetFragment
  }
}