Google CloudOverview
It is recommended to set the skip_show_database database flag for a Cloud SQL MySQL instance to on.
Rationale
The skip_show_database flag prevents users from using the SHOW DATABASES statement if they do not have the SHOW DATABASES privilege. This can improve security if you have concerns about users being able to see databases belonging to other users. Its effect depends on the SHOW DATABASES privilege: If the variable value is ON, the SHOW DATABASES statement is permitted only to users who
have the SHOW DATABASES privilege, and the statement displays all database names. If the value is OFF, SHOW DATABASES is permitted to all users, but displays the names of only those databases for which the user has the SHOW DATABASES or other privilege. This recommendation is applicable to MySQL database instances.
Remediation guidance
From Google Cloud Console
- Go to the
Cloud SQL Instancespage in the Google Cloud Console by visiting https://console.cloud.google.com/sql/instances. - Select the MySQL instance where the database flag needs to be enabled.
- Click
Edit. - Scroll down to the
Flagssection. - To set a flag that has not been set on the instance before, click
Add item, choose the flagskip_show_databasefrom the drop-down menu, and set its value toon. - Click Save.
- Confirm the changes under
Flagson theOverviewpage
Using Google Cloud CLI
- List all Cloud SQL database instances using the following command:
gcloud sql instances list
- Configure the
skip_show_databasedatabase flag for every Cloud SQL MySQL database instance using the below command:
gcloud sql instances patch <instanceName> --database-flags skip_show_database=on
Note: This command will overwrite all database flags that were previously set. To keep those and add new ones, include the values for all flags to be set on the instance; any flag not specifically included is set to its default value. For flags that do not take a value, specify the flag name followed by an equals sign ("=").
Default Value
By default skip_show_database is off.
References
- https://cloud.google.com/sql/docs/mysql/flags
- https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_skip_show_database
Additional information
WARNING: This patch modifies database flag values, which may require the instance to be restarted. Check the list of supported flags https://cloud.google.com/sql/docs/mysql/flags - to see if your instance will be restarted when this patch is submitted.
Note: Some database flag settings can affect instance availability or stability, and remove the instance from the Cloud SQL SLA. For information about these flags, see Operational Guidelines.
Note: Configuring the above flag restarts the Cloud SQL instance.
Multiple Remediation Paths
Google Cloud
SERVICE-WIDE (RECOMMENDED when many resources are affected): Enforce Organization Policies at org/folder level so new resources inherit secure defaults.
gcloud org-policies set-policy policy.yaml
ASSET-LEVEL: Use the product-specific remediation steps above for only the impacted project/resources.
PREVENTIVE: Use org policy constraints/custom constraints and enforce checks in deployment pipelines.
References for Service-Wide Patterns
- GCP Organization Policy overview: https://cloud.google.com/resource-manager/docs/organization-policy/overview
- GCP Organization policy constraints catalog: https://cloud.google.com/resource-manager/docs/organization-policy/org-policy-constraints
- gcloud org-policies: https://cloud.google.com/sdk/gcloud/reference/org-policies
Operational Rollout Workflow
Use this sequence to reduce risk and avoid repeated drift.
1. Contain at Service-Wide Scope First (Recommended)
- Google Cloud: apply organization policy constraints at org/folder scope.
gcloud org-policies set-policy policy.yaml
2. Remediate Existing Affected Assets
- Execute the control-specific Console/CLI steps documented above for each flagged resource.
- Prioritize internet-exposed and production assets first.
3. Validate and Prevent Recurrence
- Re-scan after each remediation batch.
- Track exceptions with owner and expiry date.
- Add preventive checks in IaC/CI pipelines.
Query logic
These are the stored checks tied to this control.
Ensure 'skip_show_database' database flag for Cloud SQL MySQL instance is set to 'On'
Connectors
Covered asset types
Expected check: eq []
{
cloudSqlInstances(
where: {
engine: "mysql"
cloudProvider: "gcp"
OR: [
{ dbFlags_NONE: { name: "skip_show_database" } }
{ dbFlags_SOME: { name: "skip_show_database", value: "off" } }
]
}
) {
...AssetFragment
}}
