Azure security baseline for Azure Firewall

This security baseline applies guidance from the Microsoft cloud security benchmark version 1.0 to Azure Firewall. 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 Azure Firewall.

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 Azure Firewall have been excluded. To see how Azure Firewall completely maps to the Microsoft cloud security benchmark, see the full Azure Firewall security baseline mapping file.

Security profile

The security profile summarizes high-impact behaviors of Azure Firewall, which may result in increased security considerations.

Service Behavior Attribute Value
Product Category Networking, Security
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: Tutorial: Secure your hub virtual network using Azure Firewall Manager

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
False Not Applicable Not Applicable

Feature notes: Azure Firewall is a managed service with multiple protection layers, including platform protection with NIC level NSGs (not viewable). Subnet level NSGs aren't required on the AzureFirewallSubnet, and are disabled to ensure no service interruption.

Configuration Guidance: This feature is not supported to secure this service.

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

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.

Local Authentication Methods for Data Plane Access

Description: Local authentications methods supported for data plane access, such as a local username and password. 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 for other services accessing Azure Firewall are not supported, a managed identity for Azure Firewall is used to authenticate to and retrieve certificates from Azure Key Vault.

Configuration Guidance: This feature is not supported to secure this service.

Service Principals

Description: Data plane supports authentication using service principals. 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-7: Restrict resource access based on conditions

Features

Conditional Access for Data Plane

Description: Data plane access can be controlled using Azure AD Conditional Access Policies. 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-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
False Not Applicable Not Applicable

Configuration Guidance: This feature is not supported to secure this service.

Privileged access

For more information, see the Microsoft cloud security benchmark: Privileged access.

PA-1: Separate and limit highly privileged/administrative users

Features

Local Admin Accounts

Description: Service has the concept of a local administrative account. Learn more.

Supported Enabled By Default Configuration Responsibility
False Not Applicable Not Applicable

Configuration Guidance: This feature is not supported to secure this service.

PA-7: Follow just enough administration (least privilege) principle

Features

Azure RBAC for Data Plane

Description: Azure Role-Based Access Control (Azure RBAC) can be used to managed access to service's data plane actions. Learn more.

Supported Enabled By Default Configuration Responsibility
False Not Applicable Not Applicable

Configuration Guidance: This feature is not supported to secure this service.

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

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: The customer can enable TLS inspection for traffic transiting through Azure Firewall, which creates two dedicated TLS connections: one with the Web Server (contoso.com) and another connection with the client.

The customer may also configure the firewall policy to only allow encrypted traffic.

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: Azure Firewall Premium features

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: Azure Firewall generates derived certificates from the customer certificate in Key Vault which is encrypted. The derived certificates are encrypted using Platform Keys in the backend.

Configuration Guidance: No additional configurations are required as this is enabled on a default deployment.

DP-5: Use customer-managed key option in data at rest encryption when required

Features

Data at Rest Encryption Using CMK

Description: Data at-rest encryption using customer-managed keys is supported for customer content stored by the service. 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-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: For TLS inspection, Azure Firewall requires customers to use Key Vault to provide the intermediate certificate used for generating endpoint server certificates in the data path.

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.

Note: Key Vault is recommended when storing certificates for Azure Firewall Premium.

Reference: Azure Firewall Premium 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

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 policy definitions - Network

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: Monitor Azure Firewall logs and metrics

Backup and recovery

For more information, see the Microsoft cloud security benchmark: Backup and recovery.

BR-1: Ensure regular automated backups

Features

Azure Backup

Description: The service can be backed up by the Azure Backup service. Learn more.

Supported Enabled By Default Configuration Responsibility
False Not Applicable Not Applicable

Configuration Guidance: This feature is not supported to secure this service.

Service Native Backup Capability

Description: Service supports its own native backup capability (if not using Azure Backup). Learn more.

Supported Enabled By Default Configuration Responsibility
False Not Applicable Not Applicable

Configuration Guidance: This feature is not supported to secure this service.

Next steps