Cis GCP Foundations 6.4

6.4 Ensure That the Cloud SQL Database Instance Requires All Incoming Connections To Use SSL (Automated)

Profile Applicability

• Level 1

Description

It is recommended to enforce all incoming connections to SQL database instance to use SSL.

Rationale

SQL database connections if successfully trapped (MITM); can reveal sensitive data like credentials, database queries, query outputs etc. For security, it is recommended to always use SSL encryption when connecting to your instance. This recommendation is applicable for Postgresql, MySql generation 1, MySql generation 2 and SQL Server 2017 instances.

Impact

After enforcing SSL requirement for connections, existing client will not be able to communicate with Cloud SQL database instance unless they use SSL encrypted connections to communicate to Cloud SQL database instance.

Audit

From Google Cloud Console

1. Go to https://console.cloud.google.com/sql/instances.
2. Click on an instance name to see its configuration overview.
3. In the left-side panel, select Connections.
4. In the Security section, ensure that Allow only SSL connections option is selected.

From Google Cloud CLI

1. Get the detailed configuration for every SQL database instance using the following command:

gcloud sql instances list --format=json

Ensure that section settings: ipConfiguration has the parameter sslMode set to ENCRYPTED_ONLY.

Remediation

From Google Cloud Console

1. Go to https://console.cloud.google.com/sql/instances.
2. Click on an instance name to see its configuration overview.
3. In the left-side panel, select Connections.
4. In the security section, select SSL mode as Allow only SSL connections.
5. Under Configure SSL server certificates click Create new certificate and save the setting.

From Google Cloud CLI

To enforce SSL encryption for an instance run the command:

gcloud sql instances patch INSTANCE_NAME --ssl-mode= ENCRYPTED_ONLY

Note: RESTART is required for type MySQL Generation 1 Instances (backendType: FIRST_GEN) to get this configuration in effect.

Default Value

By default parameter settings: ipConfiguration: sslMode is not set which is equivalent to sslMode:ALLOW_UNENCRYPTED_AND_ENCRYPTED.

References

1. https://cloud.google.com/sql/docs/postgres/configure-ssl-instance/

Additional Information

By default Settings: ipConfiguration has no authorizedNetworks set/configured. In that case even if by default sslMode is not set, which is equivalent to sslMode:ALLOW_UNENCRYPTED_AND_ENCRYPTED there is no risk as instance cannot be accessed outside of the network unless authorizedNetworks are configured. However, If default for sslMode is not updated to ENCRYPTED_ONLY any authorizedNetworks created later on will not enforce SSL only connection.

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