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Event Grid Namespace accepts insecure TLS versions#

Security · Event Grid Namespace · Rule · 2025_06 · Critical

Weak or deprecated transport protocols for client-server communication introduce security vulnerabilities.

Description#

The minimum version of TLS that Event Grid Namespaces 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Azure lets you disable outdated protocols and require connections to use a minimum of TLS 1.2.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#

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

Examples#

Configure with Bicep#

To deploy namespaces that pass this rule:

  • Set the properties.minimumTlsVersionAllowed property to 1.2.

For example:

Azure Bicep snippet
resource namespace 'Microsoft.EventGrid/namespaces@2025-02-15' = {
  name: name
  location: location
  identity: {
    type: 'SystemAssigned'
  }
  properties: {
    publicNetworkAccess: 'Disabled'
    minimumTlsVersionAllowed: '1.2'
    isZoneRedundant: true
  }
}

Configure with Azure template#

To deploy namespaces that pass this rule:

  • Set the properties.minimumTlsVersionAllowed property to 1.2.

For example:

Azure Template snippet
{
  "type": "Microsoft.EventGrid/namespaces",
  "apiVersion": "2025-02-15",
  "name": "[parameters('name')]",
  "location": "[parameters('location')]",
  "identity": {
    "type": "SystemAssigned"
  },
  "properties": {
    "publicNetworkAccess": "Disabled",
    "minimumTlsVersionAllowed": "1.2",
    "isZoneRedundant": true
  }
}

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