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Azure SQL DB server minimum TLS version#

Security · SQL Database · Rule · 2020_09 · Critical

Azure SQL Database servers should reject TLS versions older than 1.2.

Description#

The minimum version of TLS that Azure SQL Database servers accept is configurable. Older TLS versions are no longer considered secure by industry standards, such as PCI DSS.

Azure lets you disable outdated protocols and require connections to use a minimum of TLS 1.2. By default, TLS 1.0, TLS 1.1, and TLS 1.2 is accepted.

When clients connect using an older version of TLS that is disabled, the connection will fail.

Recommendation#

Consider configuring the minimum supported TLS version to be 1.2. Also consider enforcing this setting using Azure Policy.

Examples#

Configure with Azure template#

To deploy logical SQL Servers that pass this rule:

  • Set the properties.minimalTlsVersion to 1.2.

For example:

Azure Template snippet
{
  "type": "Microsoft.Sql/servers",
  "apiVersion": "2023-08-01-preview",
  "name": "[parameters('name')]",
  "location": "[parameters('location')]",
  "properties": {
    "publicNetworkAccess": "Disabled",
    "minimalTlsVersion": "1.2",
    "administrators": {
      "azureADOnlyAuthentication": true,
      "administratorType": "ActiveDirectory",
      "login": "[parameters('adminLogin')]",
      "principalType": "Group",
      "sid": "[parameters('adminPrincipalId')]",
      "tenantId": "[tenant().tenantId]"
    }
  }
}

Configure with Bicep#

To deploy logical SQL Servers that pass this rule:

  • Set the properties.minimalTlsVersion to 1.2.

For example:

Azure Bicep snippet
resource server 'Microsoft.Sql/servers@2023-08-01-preview' = {
  name: name
  location: location
  identity: {
    type: 'SystemAssigned'
  }
  properties: {
    publicNetworkAccess: 'Disabled'
    minimalTlsVersion: '1.2'
    administrators: {
      azureADOnlyAuthentication: true
      administratorType: 'ActiveDirectory'
      login: adminLogin
      principalType: 'Group'
      sid: adminPrincipalId
      tenantId: tenant().tenantId
    }
  }
}

Configure with Azure Verified Modules

A pre-validated module supported by Microsoft is available from the Azure Bicep public registry. To reference the module, please use the following syntax:

br/public:avm/res/sql/server:<version>

To use the latest version:

br/public:avm/res/sql/server:0.9.1

Configure with Azure Policy#

To address this issue at runtime use the following policies:

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