Description

This policy identifies Google GCE Networks that have Firewall Rules allowing unrestricted incoming traffic (0.0.0.0/0) from the internet to the standard MySQL database port: TCP/3306.

In GCP, Firewall Rules are defined at the VPC Network level. Each rule either allows or denies traffic based on its configuration. These configurations specify the type of traffic (e.g., protocols and ports) and the source or destination (e.g., IP addresses, subnets, and instances).

Rationale

Exposing a MySQL database directly to the public internet introduces significant security risks. It makes the database server a target for brute-force attacks, exploitation of known vulnerabilities, and denial-of-service attacks. Best practice is to place database servers in private network segments, allowing access only from application servers or trusted administrative hosts that require a direct connection.

Impact

All MySQL connections from outside of the network to the concerned VPC(s) can be blocked. If there is a legitimate operational need for remote access, specific trusted source IP addresses should be explicitly defined in firewall rules to whitelist access only to port 3306.

Audit

This policy flags a Google GCE Network as INCOMPLIANT if it includes at least one Firewall Rule that meets all of the following conditions:

• Source Ranges is 0.0.0.0/0 or ::/0
• Direction is INGRESS
• Allowed Protocols / Ports JSON specifies the tcp or udp protocol and the startPort - endPort range includes 3306.