Control: 4.15 Ensure the 'Minimum TLS version' for storage accounts is set to 'Version 1.2'

Description

In some cases, Azure Storage sets the minimum TLS version to be version 1.0 by default. TLS 1.0 is a legacy version and has known vulnerabilities. This minimum TLS version can be configured to be later protocols such as TLS 1.2.

TLS 1.0 has known vulnerabilities and has been replaced by later versions of the TLS protocol. Continued use of this legacy protocol affects the security of data in transit.

Remediation

From Azure Portal

Go to Storage Accounts.
For each storage account, under Settings, click Configuration.
Set the Minimum TLS version to Version 1.2.
Click Save.

From Azure CLI

az storage account update \
 --name <storage-account> \
 --resource-group <resource-group> \
 --min-tls-version TLS1_2

From PowerShell

To set the minimum TLS version, run the following command:

Set-AzStorageAccount -AccountName <STORAGEACCOUNTNAME> `
 -ResourceGroupName <RESOURCEGROUPNAME> `
 -MinimumTlsVersion TLS1_2

Default Value

If a storage account is created through the portal, the MinimumTlsVersion property for that storage account will be set to TLS 1.2.

If a storage account is created through PowerShell or CLI, the MinimumTlsVersion property for that storage account will not be set, and defaults to TLS 1.0.

Usage

Run the control in your terminal:

powerpipe control run azure_compliance.control.cis_v300_4_15

Snapshot and share results via Turbot Pipes:

powerpipe login
powerpipe control run azure_compliance.control.cis_v300_4_15 --share

SQL

This control uses a named query:

select
  sa.id as resource,
  case
    when minimum_tls_version = 'TLSEnforcementDisabled' then 'alarm'
    when minimum_tls_version = 'TLS1_2' then 'ok'
    else 'alarm'
  end as status,
  case
    when minimum_tls_version = 'TLSEnforcementDisabled' then sa.name || ' TLS enforcement is disabled.'
    when minimum_tls_version = 'TLS1_2' then sa.name || ' minimum TLS version set to ' || minimum_tls_version || '.'
    else sa.name || ' minimum TLS version set to ' || minimum_tls_version || '.'
  end as reason
  
  , sa.resource_group as resource_group
  , sub.display_name as subscription
from
  azure_storage_account sa,
  azure_subscription sub
where
  sub.subscription_id = sa.subscription_id;