Overview
It is recommended to set remote access database flag for Cloud SQL SQL Server instance to off.
Rationale
The remote access option controls the execution of stored procedures from local or remote servers on which instances of SQL Server are running. This default value for this option is 1. This grants permission to run local stored procedures from remote servers or remote stored procedures from the local server. To prevent local stored procedures from being run from a remote server or remote stored procedures from being run on the local server, this must be disabled. The Remote Access option controls the execution of local stored procedures on remote servers or remote stored procedures on local server. 'Remote access' functionality can be abused to launch a Denial-ofService (DoS) attack on remote servers by off-loading query processing to a target, hence this should be disabled. This recommendation is applicable to SQL Server database instances.
Impact
Setting custom flags via command line on certain instances will cause all omitted flags to be reset to defaults. This may cause you to lose custom flags and could result in unforeseen complications or instance restarts. Because of this, it is recommended you apply these flags changes during a period of low usage.
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 SQL Server 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 A DATABASE FLAG, choose the flagremote accessfrom the drop-down menu, and set its value tooff - Click
SAVE - Confirm the changes under
Flagson theOverviewpage
Using Google Cloud CLI
Configure the remote access database flag for every Cloud SQL SQL Server database instance using the below command:
gcloud sql instances patch <instanceName> --database-flags "remote access=off"
This command will overwrite all database flags previously set. To keep those 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 ("=").
Default Value
By default remote access is on.
References
- https://cloud.google.com/sql/docs/sqlserver/flags
- https://learn.microsoft.com/en-us/sql/database-engine/configure-windows/configure-the-user-connections-server-configuration-option?view=sql-server-ver15
- https://www.stigviewer.com/stig/ms_sql_server_2016_instance/2018-03-09/finding/V-79119
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/sqlserver/flags - to see if your instance will be restarted when this patch is submitted.
Note: Configuring the above flag restarts the Cloud SQL instance.
Service-wide remediation
Recommended when many resources are affected: fix the platform baseline first so new resources inherit the secure setting, then remediate the existing flagged resources in batches.
Google Cloud
Use organization or folder policies where available, shared project templates, logs and alerting baselines, and IaC modules so new resources inherit the secure setting.
Operational rollout
- Fix the baseline first at the account, subscription, project, cluster, or tenant scope that owns this control.
- Remediate the currently affected resources in batches, starting with internet-exposed and production assets.
- Re-scan and track approved exceptions with an owner and expiry date.
Query logic
These are the stored checks tied to this control.
Ensure 'remote access' database flag for Cloud SQL SQL Server instance is set to 'off'
Connectors
Covered asset types
Expected check: eq []
{
cloudSqlInstances(
where: {
engine: "sqlserver"
cloudProvider: "gcp"
OR: [{ dbFlags_NONE: { name: "remote access" }}, {dbFlags_SOME: {name: "remote access", value: "on"}}]
}
) {
...AssetFragment
}
}
Google Cloud