cis-azure-storage-17-12

name	cis-azure-storage-17.12
description	Ensure 'Cross Tenant Replication' is not enabled
category	cis-azure-storage
version	1.0.0
author	cyberstrike-official
tags	["cis","azure","storage","storage-accounts","replication"]
cis_id	17.12
cis_benchmark	CIS Microsoft Azure Storage Services Benchmark v1.0.0
tech_stack	["azure"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

17.12 Ensure 'Cross Tenant Replication' is not enabled (Automated)

Description

Cross Tenant Replication in Azure allows data to be replicated across multiple Azure tenants. While this feature can be beneficial for data sharing and availability, it also poses a significant security risk if not properly managed. Unauthorized data access, data leakage, and compliance violations are potential risks. Disabling Cross Tenant Replication ensures that data is not inadvertently replicated across different tenant boundaries without explicit authorization.

Rationale

Disabling Cross Tenant Replication minimizes the risk of unauthorized data access and ensures that data governance policies are strictly adhered to. This control is especially critical for organizations with stringent data security and privacy requirements, as it prevents the accidental sharing of sensitive information.

Impact

Disabling Cross Tenant Replication may affect data availability and sharing across different Azure tenants. Ensure that this change aligns with your organizational data sharing and availability requirements.

Audit Procedure

Audit from Azure Portal

1. Go to Storage Accounts.
2. For each storage account, under Data management, click Object replication.
3. Click Advanced settings.
4. Ensure Allow cross-tenant replication is not checked.

Audit from Azure CLI

az storage account list --query "[*].[name,allowCrossTenantReplication]"

The value of false should be returned for each storage account listed.

Audit from Azure Policy

Policy ID: 92a89a79-6c52-4a7e-a03f-61306fc49312 - Name: 'Storage accounts should prevent cross tenant object replication'

Expected Result

Cross Tenant Replication should be disabled (not checked) for all storage accounts. CLI output should show false for allowCrossTenantReplication for each storage account.

Remediation

Remediate from Azure Portal

1. Go to Storage Accounts.
2. For each storage account, under Data management, click Object replication.
3. Click Advanced settings.
4. Uncheck Allow cross-tenant replication.
5. Click OK.