MySQL Database server firewall rules should not permit start and end IP addresses to be 0.0.0.0

Description

MySQL Database server firewall rules should not permit start and end IP addresses to be 0.0.0.0. Adding a rule with range 0.0.0.0 to 0.0.0.0 is the same as enabling the “Allow access to Azure services” setting, which allows all connections from Azure, including from other subscriptions. Disabling this setting helps prevent malicious Azure users from connecting to your database and accessing sensitive data.

Portal Remediation Steps

Disable the “Allow access to Azure services” setting:

  • Navigate to Azure Database for MySQL Servers and select your server

  • Select Connection Security

  • Set the “Allow access to Azure services” control to OFF

To allow specific Azure services to connect to the MySQL Database server, consider setting up a virtual network service endpoint and rules.

Azure CLI Remediation Steps

  • List all firewall rules for a MySQL Database server:

    • az mysql server firewall-rule list --resource-group <your-resource-group> --server-name <your-server-name>

  • Look for rules with a start and end IP address of 0.0.0.0 and copy the rule ID

  • Delete the rule:

    • az mysql server firewall-rule delete --resource-group <your-resource-group> --server-name <your-server-name> --name <your-firewall-name>

To allow specific Azure services to connect to the MySQL Database server, consider setting up a virtual network service endpoint and rules.