Azure security baseline for Azure Cosmos DB

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

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

Security profile

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

Service Behavior Attribute	Value
Product Category	Databases
Customer can access HOST / OS	No Access
Service can be deployed into customer's virtual network	False
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	False	Customer

Configuration Guidance: Deploy the service into a virtual network. Your Azure Cosmos DB account will be exposed to the virtual network through its public IPs.

Reference: Configure access to Azure Cosmos DB from virtual networks (VNet)

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

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: Configure Azure Private Link for an Azure Cosmos account

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: Configure IP firewall in Azure Cosmos DB

Microsoft Defender for Cloud monitoring

Azure Policy built-in definitions - Microsoft.DocumentDB:

Name (Azure portal)	Description	Effect(s)	Version (GitHub)
Azure Cosmos DB accounts should have firewall rules	Firewall rules should be defined on your Azure Cosmos DB accounts to prevent traffic from unauthorized sources. Accounts that have at least one IP rule defined with the virtual network filter enabled are deemed compliant. Accounts disabling public access are also deemed compliant.	Audit, Deny, Disabled	2.0.0

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
True	False	Customer

Feature notes: Azure AD authentication is only supported on the Core (SQL) API. Other APIs only support key-based authentication.

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: Configure role-based access control with Azure Active Directory for your Azure Cosmos DB account

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	True	Microsoft

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

Reference: Secure access to data in Azure Cosmos DB

Microsoft Defender for Cloud monitoring

Azure Policy built-in definitions - Microsoft.DocumentDB:

Name (Azure portal)	Description	Effect(s)	Version (GitHub)
Cosmos DB database accounts should have local authentication methods disabled	Disabling local authentication methods improves security by ensuring that Cosmos DB database accounts exclusively require Azure Active Directory identities for authentication. Learn more at: https://docs.microsoft.com/azure/cosmos-db/how-to-setup-rbac#disable-local-auth.	Audit, Deny, Disabled	1.1.0

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	False	Customer

Feature notes: Azure AD authentication is only supported on the Core (SQL) API.

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: Configure managed identities with Azure Active Directory for your Azure Cosmos DB account

Service Principals

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

Supported	Enabled By Default	Configuration Responsibility
True	False	Customer

Feature notes: Azure AD authentication is only supported by the Core (SQL) API.

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: Configure role-based access control with Azure Active Directory for your Azure Cosmos DB account

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
True	False	Customer

Feature notes: Conditional access policies are supported where Azure AD authentication is used. Azure AD authentication is only supported on the Core (SQL) API.

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.

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

Feature notes: Cosmos DB can use primary/secondary keys (shared secrets) to control access to data. Integration of these secrets into Key Vault is not supported directly by Cosmos DB, but custom client code that uses shared secrets can use Key Vault if desired.

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-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	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: Configure role-based access control with Azure Active Directory for your Azure Cosmos DB account

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

Feature notes: Lockbox can't be implemented on Azure Cosmos DB due to the multi-tenant nature of the service.

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
True	False	Customer

Feature notes: Microsoft Purview data classification only supported the Azure Cosmos DB Core (SQL) API.

Configuration Guidance: Use Microsoft Purview to centrally scan, classify and label any sensitive data that resides in your Azure Cosmos DB account.

Reference: Connect to Azure Cosmos database (SQL API) in Microsoft Purview

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
True	False	Customer

Configuration Guidance: Use Microsoft Defender for Azure Cosmos DB to detect data exfiltration attempts.

Reference: Microsoft Defender for Azure Cosmos DB

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

Feature notes: Cosmos DB supports data encryption in transit with TLS v1.2 or greater and this cannot be disabled. Azure also provides encryption for data in transit between Azure data centers.

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

Reference: Double encryption

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: Data stored in your Azure Cosmos DB account is automatically and seamlessly encrypted with keys managed by Microsoft (service-managed keys).

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

Reference: Data encryption in Azure Cosmos DB

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
True	False	Customer

Configuration Guidance: If required for regulatory compliance, define the use case and service scope where encryption using customer-managed keys are needed. Enable and implement data at rest encryption using customer-managed key for those services.

Reference: Configure customer-managed keys for your Azure Cosmos account with Azure Key Vault

Microsoft Defender for Cloud monitoring

Azure Policy built-in definitions - Microsoft.DocumentDB:

Name (Azure portal)	Description	Effect(s)	Version (GitHub)
Azure Cosmos DB accounts should use customer-managed keys to encrypt data at rest	Use customer-managed keys to manage the encryption at rest of your Azure Cosmos DB. By default, the data is encrypted at rest with service-managed keys, but customer-managed keys are commonly required to meet regulatory compliance standards. Customer-managed keys enable the data to be encrypted with an Azure Key Vault key created and owned by you. You have full control and responsibility for the key lifecycle, including rotation and management. Learn more at https://aka.ms/cosmosdb-cmk.	audit, Audit, deny, Deny, disabled, Disabled	1.1.0

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
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: Configure customer-managed keys for your Azure Cosmos DB account with Azure Key Vault

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

Reference: Azure Policy built-in policy definitions - Cosmos DB

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 Microsoft Defender for Azure Cosmos DB to automatically detect multiple security threats.

Reference: Microsoft Defender for Azure Cosmos DB

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. Azure Cosmos DB lets you monitor your activity through Azure Monitor or custom diagnostic logs that can be analyzed with Azure Log Analytics.

Reference: Monitor Azure Cosmos DB

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
True	True	Microsoft

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

Reference: Online backup and on-demand data restore in Azure Cosmos DB

Next steps

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