cis-azure-storage-8-3

name	cis-azure-storage-8.3
description	Ensure 'SMB protocol version' is set to 'SMB 3.1.1' or higher for SMB file shares
category	cis-azure-storage
version	1.0.0
author	cyberstrike-official
tags	["cis","azure","storage","azure-files","smb","encryption"]
cis_id	8.3
cis_benchmark	CIS Microsoft Azure Storage Services Benchmark v1.0.0
tech_stack	["azure"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

8.3 Ensure 'SMB protocol version' is set to 'SMB 3.1.1' or higher for SMB file shares (Automated)

Description

Ensure that SMB file shares are configured to use the latest supported SMB protocol version. Keeping the SMB protocol updated helps mitigate risks associated with older SMB versions, which may contain vulnerabilities and lack essential security controls.

Rationale

Using the latest supported SMB protocol version enhances the security of SMB file shares by preventing the exploitation of known vulnerabilities in outdated SMB versions.

Impact

Using the latest SMB protocol version may impact client compatibility.

Audit Procedure

Audit from Azure Portal

1. Go to Storage accounts.
2. Click the name of a storage account.
3. Under Data storage, click File shares.
4. Under File share settings, click the link next to Security.
5. Under SMB protocol versions, ensure that SMB3.1.1 is the only checked protocol version.
6. Repeat steps 1-5 for each storage account.

Audit from Azure CLI

Run the following command to list storage accounts:

az storage account list

For each storage account, run the following command:

az storage account file-service-properties show --resource-group <resource-group> --account-name <storage-account>

Ensure that under protocolSettings > smb, versions is set to SMB3.1.1; only.

Audit from PowerShell

Run the following command to list storage accounts:

Get-AzStorageAccount

Run the following command to get the file service properties for a storage account in a resource group with a given name:

$storageaccountfileservice = Get-AzStorageFileServiceProperty -ResourceGroupName <resource-group> -AccountName <storage-account>

Run the following command to get the SMB protocol version setting:

$storageaccountfileservice.ProtocolSettings.Smb.Versions

Ensure that the command returns SMB3.1.1 only. Repeat for each storage account.

Expected Result

Under > , is set to only.