Cis Azure Compute 2.2.10

Ensure 'Remote debugging' is set to 'Off'

Description

Remote debugging allows an App Service deployment slot to be debugged in real-time directly in the Azure environment. When remote debugging is enabled, it opens a communication channel that could potentially be exploited by unauthorized users if not properly secured.

Rationale

Disabling remote debugging on an App Service deployment slot is primarily about enhancing security.

Remote debugging opens a communication channel that can be exploited by attackers. By disabling it, you reduce the number of potential entry points for unauthorized access.

If remote debugging is enabled without proper access controls, it can allow unauthorized users to connect to your deployment slot, potentially leading to data breaches or malicious code execution.

During a remote debugging session, sensitive information might be exposed. Disabling remote debugging helps ensure that such data remains secure. This minimizes the use of remote access tools to reduce risk.

Impact

You will not be able to connect to your deployment slot from a remote location to diagnose and fix issues in real-time. You will not be able to step through code, set breakpoints, or inspect variables and the call stack while the deployment slot is running on the server. Remote debugging is particularly useful for diagnosing issues that only occur in the production environment. Without it, you will need to rely on logs and other diagnostic tools.

Audit Procedure

Using Azure Portal

1. Go to App Services.
2. Click the name of an app.
3. Under Deployment, click Deployment slots.
4. Click the name of a deployment slot.
5. Under Settings, click Configuration.
6. In the General settings pane, under Debugging, ensure that Remote debugging is set to Off.
7. Repeat steps 1-6 for each app and deployment slot.

Using Azure CLI

Run the following command to list apps:

az webapp list

For each app, run the following command to list deployment slots:

az webapp deployment slot list --resource-group <resource-group-name> --name <app-name>

For each deployment slot, run the following command to get the remote debugging setting:

az resource show --name web --resource-group <resource-group-name> --namespace Microsoft.Web --resource-type config --parent sites/<app-name>/slots/<deployment-slot-name> --query properties.remoteDebuggingEnabled

Ensure that false is returned.

Expected Result

The remoteDebuggingEnabled property should return false.

Remediation

Using Azure Portal

1. Go to App Services.
2. Click the name of an app.
3. Under Deployment, click Deployment slots.
4. Click the name of a deployment slot.
5. Under Settings, click Configuration.
6. In the General settings pane, under Debugging, set Remote debugging to Off.
7. Click Save.
8. Click Continue.
9. Repeat steps 1-8 for each app and deployment slot requiring remediation.

Using Azure CLI

For each deployment slot requiring remediation, run the following command to disable remote debugging:

az resource update --name web --resource-group <resource-group-name> --namespace Microsoft.Web --resource-type config --parent sites/<app-name>/slots/<deployment-slot-name> --set properties.remoteDebuggingEnabled=false

Default Value

By default, remote debugging is set to off.

References

1. https://learn.microsoft.com/en-us/visualstudio/debugger/remote-debugging-azure-app-service
2. https://learn.microsoft.com/en-us/security/benchmark/azure/mcsb-posture-vulnerability-management#pv-2-audit-and-enforce-secure-configurations
3. https://learn.microsoft.com/en-us/cli/azure/webapp
4. https://learn.microsoft.com/en-us/cli/azure/resource

Profile

Level 1 | Automated