cyberstrikeus Ensure configuration is routed through the virtual network integration
Description
By default, configuration traffic for App Service deployment slots goes directly over the public route. Container image pulls and content sharing can be routed through the virtual network integration.
This recommendation should be applied after integrating an App Service deployment slot with a virtual network.
Rationale
Route container image pulls and content sharing through a virtual network integration for increased security and control.
Impact
Additional configuration may be required to ensure that traffic is routed properly.
Audit Procedure
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, ensure that vnetImagePullEnabled and vnetContentShareEnabled are set to true.
Expected Result
Both vnetImagePullEnabled and vnetContentShareEnabled properties should be set to true.
Remediation
Using Azure CLI
For each deployment slot requiring remediation, run the following command to route container image pulls and content sharing through the virtual network integration:
az resource update --resource-group <resource-group-name> --name <app-name>/slots/<deployment-slot-name> --resource-type "Microsoft.Web/sites" --set properties.vnetImagePullEnabled=true --set properties.vnetContentShareEnabled=true
Default Value
By default, configuration traffic goes directly over the public route.
Additional Information
In addition to configuring the routing for content sharing, you must also ensure that any firewall or Network Security Group configured on traffic from the subnet allow traffic to port 443 and 445.
References
- https://learn.microsoft.com/en-us/azure/app-service/overview-vnet-integration#routes
- https://learn.microsoft.com/en-us/azure/app-service/configure-vnet-integration-routing#configure-configuration-routing
- https://learn.microsoft.com/en-us/cli/azure/webapp
- https://learn.microsoft.com/en-us/cli/azure/resource
Profile
Level 2 | Automated