Control: 6.3.2 Ensure 'cross db ownership chaining' Database Flag for Cloud SQL SQL Server Instance Is Set to 'off'

Description

It is recommended to set cross db ownership chaining database flag for Cloud SQL SQL Server instance to off.

This flag is deprecated for all SQL Server versions in CGP. Going forward, you can't set its value to on. However, if you have this flag enabled, we strongly recommend that you either remove the flag from your database or set it to off. For cross-database access, use the Microsoft tutorial for signing stored procedures with a certificate.

Use the cross db ownership for chaining option to configure cross-database ownership chaining for an instance of Microsoft SQL Server. This server option allows you to control cross-database ownership chaining at the database level or to allow cross-database ownership chaining for all databases. Enabling cross db ownership is not recommended unless all of the databases hosted by the instance of SQL Server must participate in cross-database ownership chaining and you are aware of the security implications of this setting. This recommendation is applicable to SQL Server database instances.

Remediation

From Google Cloud Console

Go to the Cloud SQL Instances page in the Google Cloud Console by visiting https://console.cloud.google.com/sql/instances.
Select the SQL Server instance for which you want to enable to database flag.
Click Edit.
Scroll down to the Flags section.
To set a flag that has not been set on the instance before, click Add item, choose the flag cross db ownership chaining from the drop-down menu, and set its value to off.
Click Save.
Confirm the changes under Flags on the Overview page.

From Google Cloud CLI

Configure the cross db ownership chaining database flag for every Cloud SQL SQL Server database instance using the below command:

gcloud sql instances patch <INSTANCE_NAME> --database-flags "cross db ownership chaining"=off

Note: This command will overwrite all database flags 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

This flag is deprecated for all SQL Server versions. Going forward, you can't set its value to on.

Usage

Run the control in your terminal:

powerpipe control run gcp_compliance.control.cis_v400_6_3_2

Snapshot and share results via Turbot Pipes:

powerpipe login
powerpipe control run gcp_compliance.control.cis_v400_6_3_2 --share

SQL

This control uses a named query:

select
  self_link resource,
  case
    when database_version not like 'SQLSERVER%' then 'skip'
    when database_flags @> '[{"name":"cross db ownership chaining","value":"off"}]' then 'ok'
    else 'alarm'
  end as status,
  case
    when database_version not like 'SQLSERVER%'
      then title || ' not a SQL Server database.'
    when database_flags is null or not (database_flags @> '[{"name":"cross db ownership chaining"}]')
      then title || ' ''cross db ownership chaining'' not set.'
    when database_flags @> '[{"name":"cross db ownership chaining","value":"off"}]'
      then title || ' ''cross db ownership chaining'' database flag set to ''off''.'
    else title || ' ''cross db ownership chaining'' database flag set to ''on''.'
  end as reason
  
  , location as location, project as project
from
  gcp_sql_database_instance;