Cis Azure Database 9.8

9.8 Ensure 'Minimum TLS Version' is set to 'TLS 1.2' or higher (Automated)

Profile Applicability

• Level 1

Description

Note: It is no longer possible to set the minimal TLS version of SQL server to lower than 1.2. Azure ended support for TLS 1.0 and 1.1 in August 2025.

Setting the 'Minimum TLS version' to 'TLS 1.2' or higher reduces TLS protocol vulnerabilities by preventing the use of significantly outdated versions of TLS.

Rationale

The Secure Sockets Layer (SSL) protocol encrypts network traffic transiting between server and client.

Using only the most recent versions of SSL protocols (TLS version 1.2 and higher) eliminates susceptibility to known exploited vulnerabilities of outdated versions of TLS. If TLS 1.2 does not provide additional granular configuration options for supported cipher suites, there's a chance that default ciphers which employ Cipher Block Chaining (CBC) mode may be enabled which would introduce Padding Oracle types of vulnerabilities. TLS 1.3 does not support CBC mode ciphers by default and by default supports GCM ciphers which include an extra authentication step during the clear text to cipher text encryption process.

TLS version 1.3 is preferable where it is possible to implement.

Versions 1.0 and 1.1 of TLS are no longer considered secure. These versions should not be used or permitted where data integrity and confidentiality are required.

Impact

No impact to cost or performance.

Audit Procedure

Audit from Azure Portal

1. Go to SQL servers.
2. Select the name of a SQL server.
3. Under Security, select Networking.
4. Select Connectivity.
5. Under Encryption in transit, ensure Minimum TLS version is set to TLS 1.2 or higher.
6. Repeat steps 1-5 for each SQL server.

Audit from Azure CLI

Run the following command to list SQL servers:

az sql server list

For each SQL server, run the following command to get the minimalTlsVersion setting:

az sql server show --resource-group <resource-group> --name <sql-server> --query minimalTlsVersion

Ensure "1.2" or higher is returned.

Audit from PowerShell

Run the following command to list SQL servers:

Get-AzSqlServer

Run the following command to get the server in a resource group with a given name:

$server = Get-AzSqlServer -ResourceGroupName <resource-group> -ServerName <sql-server>

Run the following command to get the MinimalTlsVersion:

$server.MinimalTlsVersion

Ensure 1.2 or higher is returned. Repeat for each SQL server.

Audit from Azure Policy

Policy ID: 32e6bbec-16b6-44c2-be37-c5b672d103cf Name: 'Azure SQL Database should be running TLS version 1.2 or newer'

Expected Result

Minimum TLS version should be set to TLS 1.2 or higher.

Remediation

Remediate from Azure Portal

1. Go to SQL servers.
2. Select the name of a SQL server.
3. Under Security, select Networking.
4. Select Connectivity.
5. Under Encryption in transit, select TLS 1.2 or higher from the dropdown menu next to Minimum TLS version.
6. Select Save.
7. Repeat steps 1-6 for each SQL server requiring remediation.

Remediate from Azure CLI

For each SQL server requiring remediation, run the following command:

az sql server update --resource-group <resource-group> --name <sql-server> --minimal-tls-version 1.2

Remediate from PowerShell

For each SQL server requiring remediation, run the following command:

Set-AzSqlServer -ResourceGroupName <resource-group> -ServerName <sql-server> -MinimalTlsVersion "1.2"

Default Value

By default, the Minimum TLS version is set to TLS 1.2.

References

1. https://learn.microsoft.com/en-us/azure/azure-sql/database/connectivity-settings?view=azuresql
2. https://learn.microsoft.com/en-us/security/benchmark/azure/mcsb-data-protection#dp-3-encrypt-sensitive-data-in-transit

Profile

• Level 1