SQL Server must protect against a user falsely repudiating by ensuring the NT AUTHORITY SYSTEM account is not used for administration.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-213934	SQL6-D0-004100	SV-213934r754577_rule		High

Description
Non-repudiation of actions taken is required in order to maintain data integrity. Examples of particular actions taken by individuals include creating information, sending a message, approving information (e.g., indicating concurrence or signing a contract), and receiving a message. Non-repudiation protects against later claims by a user of not having created, modified, or deleted a particular data item or collection of data in the database. In designing a database, the organization must define the types of data and the user actions that must be protected from repudiation. The implementation must then include building audit features into the application data tables and configuring the DBMS's audit tools to capture the necessary audit trail. Design and implementation also must ensure that applications pass individual user identification to the DBMS, even where the application connects to the DBMS with a standard, shared account. Any user with enough access to the server can execute a task that will be run as NT AUTHORITY\SYSTEM either using task scheduler or other tools. At this point, NT AUTHORITY\SYSTEM essentially becomes a shared account because the operating system and SQL Server are unable to determine who created the process. Prior to SQL Server 2012, NT AUTHORITY\SYSTEM was a member of the sysadmin role by default. This allowed jobs/tasks to be executed in SQL Server without the approval or knowledge of the DBA because it looked like operating system activity.

Description

Non-repudiation of actions taken is required in order to maintain data integrity. Examples of particular actions taken by individuals include creating information, sending a message, approving information (e.g., indicating concurrence or signing a contract), and receiving a message. Non-repudiation protects against later claims by a user of not having created, modified, or deleted a particular data item or collection of data in the database. In designing a database, the organization must define the types of data and the user actions that must be protected from repudiation. The implementation must then include building audit features into the application data tables and configuring the DBMS's audit tools to capture the necessary audit trail. Design and implementation also must ensure that applications pass individual user identification to the DBMS, even where the application connects to the DBMS with a standard, shared account. Any user with enough access to the server can execute a task that will be run as NT AUTHORITY\SYSTEM either using task scheduler or other tools. At this point, NT AUTHORITY\SYSTEM essentially becomes a shared account because the operating system and SQL Server are unable to determine who created the process. Prior to SQL Server 2012, NT AUTHORITY\SYSTEM was a member of the sysadmin role by default. This allowed jobs/tasks to be executed in SQL Server without the approval or knowledge of the DBA because it looked like operating system activity.

STIG	Date
MS SQL Server 2016 Instance Security Technical Implementation Guide	2022-09-12

Details

Check Text ( C-15151r313585_chk )
Execute the following queries. The first query checks for Clustering and Availability Groups being provisioned in the Database Engine. The second query lists permissions granted to the Local System account. SELECT SERVERPROPERTY('IsClustered') AS [IsClustered], SERVERPROPERTY('IsHadrEnabled') AS [IsHadrEnabled] EXECUTE AS LOGIN = 'NT AUTHORITY\SYSTEM' SELECT * FROM fn_my_permissions(NULL, 'server') REVERT GO If IsClustered returns 1, IsHadrEnabled returns 0, and any permissions have been granted to the Local System account beyond "CONNECT SQL", "VIEW SERVER STATE", and "VIEW ANY DATABASE", this is a finding. If IsHadrEnabled returns 1 and any permissions have been granted to the Local System account beyond "CONNECT SQL", "CREATE AVAILABILITY GROUP", "ALTER ANY AVAILABILITY GROUP", "VIEW SERVER STATE", and "VIEW ANY DATABASE", this is a finding. If both IsClustered and IsHadrEnabled return 0 and any permissions have been granted to the Local System account beyond "CONNECT SQL" and "VIEW ANY DATABASE", this is a finding.

Check Text ( C-15151r313585_chk )

Execute the following queries. The first query checks for Clustering and Availability Groups being provisioned in the Database Engine. The second query lists permissions granted to the Local System account.

SELECT
SERVERPROPERTY('IsClustered') AS [IsClustered],
SERVERPROPERTY('IsHadrEnabled') AS [IsHadrEnabled]

EXECUTE AS LOGIN = 'NT AUTHORITY\SYSTEM'

SELECT * FROM fn_my_permissions(NULL, 'server')

REVERT

GO

If IsClustered returns 1, IsHadrEnabled returns 0, and any permissions have been granted to the Local System account beyond "CONNECT SQL", "VIEW SERVER STATE", and "VIEW ANY DATABASE", this is a finding.

If IsHadrEnabled returns 1 and any permissions have been granted to the Local System account beyond "CONNECT SQL", "CREATE AVAILABILITY GROUP", "ALTER ANY AVAILABILITY GROUP", "VIEW SERVER STATE", and "VIEW ANY DATABASE", this is a finding.

If both IsClustered and IsHadrEnabled return 0 and any permissions have been granted to the Local System account beyond "CONNECT SQL" and "VIEW ANY DATABASE", this is a finding.

Fix Text (F-15149r313586_fix)
Remove permissions that were identified as not allowed in the check content. USE Master; REVOKE TO [NT AUTHORITY\SYSTEM] GO To grant permissions to services or applications, utilize the Service SID of the service or a domain service account.