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An inbound network security rule allows traffic from /0.

Default Severity: critical

Explanation

Network security rules should not use very broad subnets.

Where possible, segments should be broken into smaller subnets.

Possible Impact

The port is exposed for ingress from the internet

Suggested Resolution

Set a more restrictive cidr range

Insecure Example

The following example will fail the azure-network-no-public-ingress check. 

 resource "azurerm_network_security_rule" "bad_example" {
    direction = "Inbound"
    source_address_prefix = "0.0.0.0/0"
    access = "Allow"
 }

Secure Example

The following example will pass the azure-network-no-public-ingress check. 

 resource "azurerm_network_security_rule" "good_example" {
    direction = "Inbound"
    destination_address_prefix = "10.0.0.0/16"
    access = "Allow"
 }