# Source: https://docs.datadoghq.com/security/default_rules/def-000-ht8.md

---
title: MySQL instance should have the 'skip_show_database' flag set to 'on'
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > OOTB Rules > MySQL instance should have the
  'skip_show_database' flag set to 'on'
---

# MySQL instance should have the 'skip_show_database' flag set to 'on'
 
## Description{% #description %}

It is recommended that for Cloud SQL Instances, you set the `skip_show_database` database flag to `ON`.

## Rationale{% #rationale %}

The `skip_show_database` database flag prevents people 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. The `skip_show_database` flag's effect depends on the `SHOW DATABASES` privilege: If the variable value is `ON`, the `SHOW DATABASES` statement is permitted only for users who have the `SHOW DATABASES` privilege, and the statement displays all database names. If the value is `OFF`, `SHOW DATABASES` is permitted for all users, but displays the names of only those databases for which the user has `SHOW DATABASES` or other privilege. This recommendation is applicable to MySQL database instances.

## Remediation{% #remediation %}

## Using console{% #using-console %}

1. Go to the [Cloud SQL Instances page](https://console.cloud.google.com/sql/instances) in the Google Cloud Console.
1. Select the MySQL instance for which you want to enable the database flag.
1. Click **Edit**.
1. Scroll down to the **Flags** section.
1. To set a flag that has not been set on the instance before, click **Add item**, choose the flag `skip_show_database` from the drop-down menu, and set its value to `ON`.
1. Click **Save** to save your changes.
1. Confirm your changes under **Flags** on the **Overview** page.

## Using command line:{% #using-command-line %}

1. To list all Cloud SQL database Instances, run: `gcloud sql instances list`

1. Configure the `skip_show_database` database flag for every Cloud SQL MySQL database instance using the following command:

   ```
   gcloud sql instances patch INSTANCE_NAME --database-flags
   skip_show_database=on
   ```

**Note**: This command overwrites all database flags previously set. To keep the previously set flags and add new ones, include the values for all flags you want 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 (`=`).

## References{% #references %}

1. [https://cloud.google.com/sql/docs/mysql/flags](https://cloud.google.com/sql/docs/mysql/flags)
1. [https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_skip_show_database](https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_skip_show_database)

## Additional information{% #additional-information %}

**Warning**: This patch modifies database flag values, which may require your 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.

## CIS controls{% #cis-controls %}

Version 8, 3.3 - Configure Data Access Control Lists

- Configure data access control lists based on a user's need to know. Apply data access control lists, also known as access permissions, to local and remote file systems, databases, and applications.