Azure Storage Account default network access is set to Allow

Description

Restricting default network access helps to provide an additional layer of security. By default, storage accounts accept connections from clients on any network. To limit access to selected networks, the default action must be changed.

We recommend you configure storage accounts to deny access to traffic from all networks, including internet traffic. At an appropriate time, access can be granted to traffic from specific Azure Virtual networks, allowing a secure network boundary for specific applications to be built. Access can also be granted to public internet IP address ranges enabling connections from specific internet or on-premises clients. When network rules are configured only applications from allowed networks can access a storage account. When calling from an allowed network applications continue to require authorization, such as a valid access key or SAS token, to access the storage account.

Fix - Runtime

Azure Portal

To change the policy using the Azure Portal, follow these steps:

1. Log in to the Azure Portal at https://portal.azure.com.
2. Navigate to Storage Accounts.
3. For each storage account:
   a) Navigate to Settings menu.
   b) Click Firewalls and virtual networks.
   c) For selected networks, select Allow access.
   d) Add rules to allow traffic from specific network.
   e) To apply changes,click Save.

CLI Command

To update default-action to Deny, use the following command:

az storage account update 
--name <StorageAccountName> 
--resource-group <resourceGroupName> 
--default-action Deny

Fix - Buildtime

Terraform

• Resource: azurerm_storage_account_network_rules
• Argument: default_action

resource "azurerm_storage_account_network_rules" "test" {
    resource_group_name  = azurerm_resource_group.test.name
    storage_account_name = azurerm_storage_account.test.name

+   default_action             = "Deny"
}

In a Storage Account:

```go azurerm_storage_account.test.tf resource "azurerm_storage_account" "test" { name = var.watcher resource_group_name = azurerm_resource_group.test.name location = azurerm_resource_group.test.location

• network_rules {
• default_action="Deny"
• }

account_tier = "Standard" account_kind = "StorageV2" account_replication_type = "LRS" enable_https_traffic_only = true } ```

Suppression Advice

This can trigger incorrectly on azurerm_storage_account when using correctly configured azurerm_storage_account_network_rules, if this occurs suppression is reasonable.