Azure security baseline for Azure Arc-enabled servers

This security baseline applies guidance from the Microsoft cloud security benchmark version 1.0 to Azure Arc-enabled servers. 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 Arc-enabled servers.

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

Security profile

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

Service Behavior Attribute	Value
Product Category	Hybrid/Multi-Cloud, MGMT/Governance
Customer can access HOST / OS	No Access
Service can be deployed into customer's virtual network	False
Stores customer content at rest	False

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
False	Not Applicable	Not Applicable

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

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: Use Azure Private Link to securely connect servers to Azure Arc

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
True	False	Customer

Configuration Guidance: Disable public network access either using the service-level IP ACL filtering rule or a toggling switch for public network access.

Reference: Use Azure Private Link to securely connect servers to Azure Arc

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
True	True	Microsoft

Feature notes: There is no customer-facing data plane API.

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

Reference: Identity and access control for Azure Arc-enabled servers

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
True	False	Customer

Feature notes: Local authentication is only used when connecting to the server using SSH or Windows Admin Center. Avoid the usage of local authentication methods or accounts, these should be disabled wherever possible. Instead use Azure AD to authenticate where possible.

Configuration Guidance: Restrict the use of local authentication methods for data plane access. Instead, use Azure Active Directory (Azure AD) as the default authentication method to control your data plane access.

Reference: SSH access to Azure Arc-enabled servers

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
True	True	Microsoft

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

Reference: Authenticate against Azure resources with Azure Arc-enabled servers

Service Principals

Description: Data plane supports authentication using service principals. Learn more.

Supported	Enabled By Default	Configuration Responsibility
True	False	Customer

Configuration Guidance: There is no current Microsoft guidance for this feature configuration. Please review and determine if your organization wants to configure this security feature.

Reference: Create a service principal for onboarding at scale

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
True	False	Customer

Feature notes: Avoid the usage of local authentication methods or accounts, these should be disabled wherever possible. Instead use Azure AD to authenticate where possible.

Configuration Guidance: If not required for routine administrative operations, disable or restrict any local admin accounts for only emergency use.

Reference: SSH access to Azure Arc-enabled servers

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
True	True	Microsoft

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

Reference: Identity and access control for Azure Arc-enabled servers

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-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	True	Microsoft

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

Reference: Network topology and connectivity for Azure Arc-enabled servers

Microsoft Defender for Cloud monitoring

Azure Policy built-in definitions - Microsoft.HybridCompute:

Name (Azure portal)	Description	Effect(s)	Version (GitHub)
Windows machines should be configured to use secure communication protocols	To protect the privacy of information communicated over the Internet, your machines should use the latest version of the industry-standard cryptographic protocol, Transport Layer Security (TLS). TLS secures communications over a network by encrypting a connection between machines.	AuditIfNotExists, Disabled	4.1.1

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

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

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 definitions for Azure Arc-enabled servers

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
True	False	Customer

Configuration Guidance: Use Azure Active Directory (Azure AD) as the default authentication method to control your management plane access. When you get an alert from Microsoft Defender for Key Vault, investigate and respond to the alert.

Reference: Introduction to Microsoft Defender for Servers

Microsoft Defender for Cloud monitoring

Azure Policy built-in definitions - Microsoft.HybridCompute:

Name (Azure portal)	Description	Effect(s)	Version (GitHub)
Windows Defender Exploit Guard should be enabled on your machines	Windows Defender Exploit Guard uses the Azure Policy Guest Configuration agent. Exploit Guard has four components that are designed to lock down devices against a wide variety of attack vectors and block behaviors commonly used in malware attacks while enabling enterprises to balance their security risk and productivity requirements (Windows only).	AuditIfNotExists, Disabled	2.0.0

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
False	Not Applicable	Not Applicable

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

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

• See the Microsoft cloud security benchmark overview
• Learn more about Azure security baselines