Azure security baseline for Application Gateway
This security baseline applies guidance from the Microsoft cloud security benchmark version 1.0 to Application Gateway. The Microsoft cloud security benchmark provides recommendations on how you can secure your cloud solutions on Azure. The content is grouped by the security controls defined by the Microsoft cloud security benchmark and the related guidance applicable to Application Gateway.
You can monitor this security baseline and its recommendations using Microsoft Defender for Cloud. Azure Policy definitions will be listed in the Regulatory Compliance section of the Microsoft Defender for Cloud portal page.
When a feature has relevant Azure Policy Definitions, they are listed in this baseline to help you measure compliance with the Microsoft cloud security benchmark controls and recommendations. Some recommendations may require a paid Microsoft Defender plan to enable certain security scenarios.
Note
Features not applicable to Application Gateway have been excluded. To see how Application Gateway completely maps to the Microsoft cloud security benchmark, see the full Application Gateway security baseline mapping file.
Security profile
The security profile summarizes high-impact behaviors of Application Gateway, which may result in increased security considerations.
| Service Behavior Attribute | Value |
|---|---|
| Product Category | Networking |
| Customer can access HOST / OS | No Access |
| Service can be deployed into customer's virtual network | True |
| Stores customer content at rest | True |
Network security
For more information, see the Microsoft cloud security benchmark: Network security.
NS-1: Establish network segmentation boundaries
Features
Virtual Network Integration
Description: Service supports deployment into customer's private Virtual Network (VNet). Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| True | True | Microsoft |
Configuration Guidance: No additional configurations are required as this is enabled on a default deployment.
Reference: Application Gateway infrastructure configuration
Network Security Group Support
Description: Service network traffic respects Network Security Groups rule assignment on its subnets. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| True | False | Customer |
Configuration Guidance: Use network security groups (NSG) to restrict or monitor traffic by port, protocol, source IP address, or destination IP address. Create NSG rules to restrict your service's open ports (such as preventing management ports from being accessed from untrusted networks). Be aware that by default, NSGs deny all inbound traffic but allow traffic from virtual network and Azure Load Balancers.
Reference: Network security groups
Microsoft Defender for Cloud monitoring
Azure Policy built-in definitions - Microsoft.Network:
| Name (Azure portal) |
Description | Effect(s) | Version (GitHub) |
|---|---|---|---|
| Subnets should be associated with a Network Security Group | Protect your subnet from potential threats by restricting access to it with a Network Security Group (NSG). NSGs contain a list of Access Control List (ACL) rules that allow or deny network traffic to your subnet. | AuditIfNotExists, Disabled | 3.0.0 |
NS-2: Secure cloud services with network controls
Features
Azure Private Link
Description: Service native IP filtering capability for filtering network traffic (not to be confused with NSG or Azure Firewall). Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| True | False | Customer |
Configuration Guidance: Deploy private endpoints for all Azure resources that support the Private Link feature, to establish a private access point for the resources.
Reference: Configure Azure Application Gateway Private Link (preview)
Disable Public Network Access
Description: Service supports disabling public network access either through using service-level IP ACL filtering rule (not NSG or Azure Firewall) or using a 'Disable Public Network Access' toggle switch. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| False | Not Applicable | Not Applicable |
Feature notes: Limited public connectivity is required for the management of Application Gateway.
For more information, please visit: Application Gateway infrastructure configuration
Configuration Guidance: This feature is not supported to secure this service.
Identity management
For more information, see the Microsoft cloud security benchmark: Identity management.
IM-1: Use centralized identity and authentication system
Features
Azure AD Authentication Required for Data Plane Access
Description: Service supports using Azure AD authentication for data plane access. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| False | Not Applicable | Not Applicable |
Configuration Guidance: This feature is not supported to secure this service.
IM-3: Manage application identities securely and automatically
Features
Managed Identities
Description: Data plane actions support authentication using managed identities. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| False | Not Applicable | Not Applicable |
Feature notes: Though managed identities from other services may not authenticate to Application Gateway, a managed identity can be used by Application Gateway to authenticate to Azure Key Vault and is optional to be specified at the deployment time. The service honors Azure RBAC controls.
Configuration Guidance: This feature is not supported to secure this service.
IM-8: Restrict the exposure of credential and secrets
Features
Service Credential and Secrets Support Integration and Storage in Azure Key Vault
Description: Data plane supports native use of Azure Key Vault for credential and secrets store. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| True | False | Customer |
Feature notes: When the customer uploads a TLS certificate, it is automatically stored within a managed Azure Key vault Service.
Application Gateway v1 does not support Azure Key Vault integration. Credentials and certificates are stored in a different secret store.
Configuration Guidance: Ensure that secrets and credentials are stored in secure locations such as Azure Key Vault, instead of embedding them into code or configuration files.
Reference: Configure an Application Gateway with TLS termination using the Azure portal
Privileged access
For more information, see the Microsoft cloud security benchmark: Privileged access.
PA-8: Determine access process for cloud provider support
Features
Customer Lockbox
Description: Customer Lockbox can be used for Microsoft support access. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| False | Not Applicable | Not Applicable |
Configuration Guidance: This feature is not supported to secure this service.
Data protection
For more information, see the Microsoft cloud security benchmark: Data protection.
DP-1: Discover, classify, and label sensitive data
Features
Sensitive Data Discovery and Classification
Description: Tools (such as Azure Purview or Azure Information Protection) can be used for data discovery and classification in the service. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| False | Not Applicable | Not Applicable |
Feature notes: Apart from resource configuration (which includes customer's TLS server certificates), Application Gateway only stores transient data while proxying the requests to customers backend.
Configuration Guidance: This feature is not supported to secure this service.
DP-2: Monitor anomalies and threats targeting sensitive data
Features
Data Leakage/Loss Prevention
Description: Service supports DLP solution to monitor sensitive data movement (in customer's content). Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| False | Not Applicable | Not Applicable |
Configuration Guidance: This feature is not supported to secure this service.
DP-3: Encrypt sensitive data in transit
Features
Data in Transit Encryption
Description: Service supports data in-transit encryption for data plane. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| True | False | Customer |
Feature notes: Customer's resource configuration data is always transported through TLS channels in the control plane. For the data plane, the service lets customer choose between TCP and TLS variants. Customers choose based on their own needs.
Configuration Guidance: Enable secure transfer in services where there is a native data in transit encryption feature built in. Enforce HTTPS on any web applications and services and ensure TLS v1.2 or later is used. Legacy versions such as SSL 3.0, TLS v1.0 should be disabled. For remote management of Virtual Machines, use SSH (for Linux) or RDP/TLS (for Windows) instead of an unencrypted protocol.
Reference: Overview of TLS termination and end to end TLS with Application Gateway
DP-4: Enable data at rest encryption by default
Features
Data at Rest Encryption Using Platform Keys
Description: Data at-rest encryption using platform keys is supported, any customer content at rest is encrypted with these Microsoft managed keys. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| True | True | Microsoft |
Feature notes: Customer's data regarding resource configuration is stored in an encryption-enabled storage account and secrets are stored in a managed Azure Key Vault. Only resource configuration data is sent into Kusto for DRI/dev analytics.
Since Application Gateway is proxying product, it doesn't store customer's runtime data traffic and simply proxies it over to the backend. The service does temporarily have the network traffic in an unencrypted form in memory while proxying it to the backend/client.
Configuration Guidance: No additional configurations are required as this is enabled on a default deployment.
DP-6: Use a secure key management process
Features
Key Management in Azure Key Vault
Description: The service supports Azure Key Vault integration for any customer keys, secrets, or certificates. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| False | Not Applicable | Not Applicable |
Configuration Guidance: This feature is not supported to secure this service.
DP-7: Use a secure certificate management process
Features
Certificate Management in Azure Key Vault
Description: The service supports Azure Key Vault integration for any customer certificates. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| True | False | Customer |
Feature notes: When the customer uploads a TLS certificate, it is automatically stored within a managed Azure Key vault Service.
Application Gateway v1 does not support Azure Key Vault integration. Credentials and certificates are stored in a different secret store.
Configuration Guidance: Use Azure Key Vault to create and control the certificate lifecycle, including creation, importing, rotation, revocation, storage, and purging of the certificate. Ensure the certificate generation follows defined standards without using any insecure properties, such as: insufficient key size, overly long validity period, insecure cryptography. Setup automatic rotation of the certificate in Azure Key Vault and the Azure service (if supported) based on a defined schedule or when there is a certificate expiration. If automatic rotation is not supported in the application, ensure they are still rotated using manual methods in Azure Key Vault and the application.
Reference: TLS termination with Key Vault certificates
Asset management
For more information, see the Microsoft cloud security benchmark: Asset management.
AM-2: Use only approved services
Features
Azure Policy Support
Description: Service configurations can be monitored and enforced via Azure Policy. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| True | False | Customer |
Feature notes: Application Gateways are provisioned into the customer's VNet and, barring certain exemptions needed for management traffic, the customer can apply all the needed Azure Policies on a VNet.
Configuration Guidance: Use Microsoft Defender for Cloud to configure Azure Policy to audit and enforce configurations of your Azure resources. Use Azure Monitor to create alerts when there is a configuration deviation detected on the resources. Use Azure Policy [deny] and [deploy if not exists] effects to enforce secure configuration across Azure resources.
Reference: Azure Policy built-in definitions for Azure networking services
Logging and threat detection
For more information, see the Microsoft cloud security benchmark: Logging and threat detection.
LT-1: Enable threat detection capabilities
Features
Microsoft Defender for Service / Product Offering
Description: Service has an offering-specific Microsoft Defender solution to monitor and alert on security issues. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| False | Not Applicable | Not Applicable |
Configuration Guidance: This feature is not supported to secure this service.
LT-4: Enable logging for security investigation
Features
Azure Resource Logs
Description: Service produces resource logs that can provide enhanced service-specific metrics and logging. The customer can configure these resource logs and send them to their own data sink like a storage account or log analytics workspace. Learn more.
| Supported | Enabled By Default | Configuration Responsibility |
|---|---|---|
| True | False | Customer |
Configuration Guidance: Enable resource logs for the service. For example, Key Vault supports additional resource logs for actions that get a secret from a key vault or and Azure SQL has resource logs that track requests to a database. The content of resource logs varies by the Azure service and resource type.
Reference: Backend health and diagnostic logs for Application Gateway
Next steps
- See the Microsoft cloud security benchmark overview
- Learn more about Azure security baselines