Allowing unrestricted, public access to cloud services creates a significant vulnerability, as it opens up the application to external attacks. When public access is enabled, without the implementation of proper firewall rules, your Azure SQL Servers are left exposed and unsecured, making them highly susceptible to unauthorized access, data breaches, and other malicious activities.
In Azure Console -
In Terraform -
References:
https://learn.microsoft.com/en-us/azure/azure-sql/database/firewall-configure?view=azuresql
https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/mssql_firewall_rule