SQL Server must generate Trace or Audit records when unsuccessful attempts to delete privileges/permissions occur.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-67927	SQL4-00-037000	SV-82417r1_rule		Medium

Description
Changes in the permissions, privileges, and roles granted to users and roles must be tracked. Without an audit trail, unauthorized elevation or restriction of privileges could go undetected. Elevated privileges give users access to information and functionality that they should not have; restricted privileges wrongly deny access to authorized users. In SQL Server, deleting permissions is typically done via the REVOKE or DENY command; or with the ALTER SERVER ROLE . . . DROP MEMBER . . . and/or ALTER ROLE . . . DROP MEMBER . . . statements. To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones. Use of SQL Server Audit is recommended. All features of SQL Server Audit are available in the Enterprise and Developer editions of SQL Server 2014. It is not available at the database level in other editions. For this or legacy reasons, the instance may be using SQL Server Trace for auditing, which remains an acceptable solution for the time being. Note, however, that Microsoft intends to remove most aspects of Trace at some point after SQL Server 2016.

Description

Changes in the permissions, privileges, and roles granted to users and roles must be tracked. Without an audit trail, unauthorized elevation or restriction of privileges could go undetected. Elevated privileges give users access to information and functionality that they should not have; restricted privileges wrongly deny access to authorized users. In SQL Server, deleting permissions is typically done via the REVOKE or DENY command; or with the ALTER SERVER ROLE . . . DROP MEMBER . . . and/or ALTER ROLE . . . DROP MEMBER . . . statements. To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones. Use of SQL Server Audit is recommended. All features of SQL Server Audit are available in the Enterprise and Developer editions of SQL Server 2014. It is not available at the database level in other editions. For this or legacy reasons, the instance may be using SQL Server Trace for auditing, which remains an acceptable solution for the time being. Note, however, that Microsoft intends to remove most aspects of Trace at some point after SQL Server 2016.

STIG	Date
MS SQL Server 2014 Instance Security Technical Implementation Guide	2016-06-27

Details

Check Text ( C-68497r1_chk )
If neither SQL Server Audit nor SQL Server Trace is in use for audit purposes, this is a finding. Obtain the list of locally-defined security tables (if any) that require tracking of Insert-Update-Delete operations. If SQL Server Trace is in use for audit purposes, review these tables for the existence of triggers to raise a custom event on each Insert-Update-Delete operation. If such triggers are not present, this is a finding. Check to see that all required events are being audited. From the query prompt: SELECT * FROM sys.traces; All currently defined traces for the SQL server instance will be listed. If no traces are returned, this is a finding. Determine the trace(s) being used for the auditing requirement. In the following, replace # with a trace ID being used for the auditing requirements. From the query prompt: SELECT DISTINCT(eventid) FROM sys.fn_trace_geteventinfo(#); The following required event IDs should all be among those listed; if not, this is a finding: 42 -- SP:Starting 43 -- SP:Completed 82-91 -- User-defined Event (required only where there are locally-defined security tables or procedures) 102 -- Audit Database Scope GDR 103 -- Audit Object GDR Event 104 -- Audit AddLogin Event 105 -- Audit Login GDR Event 108 -- Audit Add Login to Server Role Event 109 -- Audit Add DB User Event 110 -- Audit Add Member to DB Role Event 111 -- Audit Add Role Event 162 -- User error message 170 -- Audit Server Scope GDR Event 171 -- Audit Server Object GDR Event 172 -- Audit Database Object GDR Event 173 -- Audit Server Operation Event 177 -- Audit Server Principal Management Event If SQL Server Audit is in use, proceed as follows. The basic SQL Server Audit configuration provided in the supplemental file Audit.sql uses broad, server-level audit action groups for this purpose. SQL Server Audit's flexibility makes other techniques possible. If an alternative technique is in use and demonstrated effective, this is not a finding. Determine the name(s) of the server audit specification(s) in use. Run the following code to verify that all GRANT, ALTER SERVER ROLE . . . ADD MEMBER . . ., and/or ALTER ROLE . . . ADD MEMBER . . . actions, all INSERT and UPDATE actions on any locally-defined permissions tables, and all EXECUTE actions on any system or locally-defined permissions-related procedures and functions, are being audited: USE [master]; GO SELECT * FROM sys.server_audit_specification_details WHERE server_specification_id = (SELECT server_specification_id FROM sys.server_audit_specifications WHERE [name] = '') AND audit_action_name IN ( 'DATABASE_OBJECT_OWNERSHIP_CHANGE_GROUP', 'DATABASE_OBJECT_PERMISSION_CHANGE_GROUP', 'DATABASE_OWNERSHIP_CHANGE_GROUP', 'DATABASE_PERMISSION_CHANGE_GROUP', 'DATABASE_ROLE_MEMBER_CHANGE_GROUP', 'SCHEMA_OBJECT_OWNERSHIP_CHANGE_GROUP', 'SCHEMA_OBJECT_PERMISSION_CHANGE_GROUP', 'SERVER_OBJECT_OWNERSHIP_CHANGE_GROUP', 'SERVER_OBJECT_PERMISSION_CHANGE_GROUP', 'SERVER_PERMISSION_CHANGE_GROUP', 'SERVER_ROLE_MEMBER_CHANGE_GROUP', 'SCHEMA_OBJECT_ACCESS_GROUP' ); GO Examine the list produced by the query. If any locally-defined permissions tables, procedures, or functions exist, and the list does not include the audit action group SCHEMA_OBJECT_ACCESS_GROUP, this is a finding. If any of the other audit action groups specified in the WHERE clause are not included in the list, this is a finding. If the audited_result column is not "FAILURE" or "SUCCESS AND FAILURE" on every row, this is a finding.

Check Text ( C-68497r1_chk )

If neither SQL Server Audit nor SQL Server Trace is in use for audit purposes, this is a finding.

Obtain the list of locally-defined security tables (if any) that require tracking of Insert-Update-Delete operations.

If SQL Server Trace is in use for audit purposes, review these tables for the existence of triggers to raise a custom event on each Insert-Update-Delete operation.

If such triggers are not present, this is a finding.

Check to see that all required events are being audited. From the query prompt:
SELECT * FROM sys.traces;

All currently defined traces for the SQL server instance will be listed.

If no traces are returned, this is a finding.

Determine the trace(s) being used for the auditing requirement.
In the following, replace # with a trace ID being used for the auditing requirements.
From the query prompt:
SELECT DISTINCT(eventid) FROM sys.fn_trace_geteventinfo(#);

The following required event IDs should all be among those listed; if not, this is a finding:

42 -- SP:Starting
43 -- SP:Completed
82-91 -- User-defined Event (required only where there are locally-defined security tables or procedures)
102 -- Audit Database Scope GDR
103 -- Audit Object GDR Event
104 -- Audit AddLogin Event
105 -- Audit Login GDR Event
108 -- Audit Add Login to Server Role Event
109 -- Audit Add DB User Event
110 -- Audit Add Member to DB Role Event
111 -- Audit Add Role Event
162 -- User error message
170 -- Audit Server Scope GDR Event
171 -- Audit Server Object GDR Event
172 -- Audit Database Object GDR Event
173 -- Audit Server Operation Event
177 -- Audit Server Principal Management Event

If SQL Server Audit is in use, proceed as follows.

The basic SQL Server Audit configuration provided in the supplemental file Audit.sql uses broad, server-level audit action groups for this purpose. SQL Server Audit's flexibility makes other techniques possible.

If an alternative technique is in use and demonstrated effective, this is not a finding.

Determine the name(s) of the server audit specification(s) in use.

Run the following code to verify that all GRANT, ALTER SERVER ROLE . . . ADD MEMBER . . ., and/or ALTER ROLE . . . ADD MEMBER . . . actions, all INSERT and UPDATE actions on any locally-defined permissions tables, and all EXECUTE actions on any system or locally-defined permissions-related procedures and functions, are being audited:
USE [master];
GO
SELECT * FROM sys.server_audit_specification_details WHERE server_specification_id =
(SELECT server_specification_id FROM sys.server_audit_specifications WHERE [name] = '')
AND audit_action_name IN
(
'DATABASE_OBJECT_OWNERSHIP_CHANGE_GROUP',
'DATABASE_OBJECT_PERMISSION_CHANGE_GROUP',
'DATABASE_OWNERSHIP_CHANGE_GROUP',
'DATABASE_PERMISSION_CHANGE_GROUP',
'DATABASE_ROLE_MEMBER_CHANGE_GROUP',
'SCHEMA_OBJECT_OWNERSHIP_CHANGE_GROUP',
'SCHEMA_OBJECT_PERMISSION_CHANGE_GROUP',
'SERVER_OBJECT_OWNERSHIP_CHANGE_GROUP',
'SERVER_OBJECT_PERMISSION_CHANGE_GROUP',
'SERVER_PERMISSION_CHANGE_GROUP',
'SERVER_ROLE_MEMBER_CHANGE_GROUP',
'SCHEMA_OBJECT_ACCESS_GROUP'
);
GO

Examine the list produced by the query.

If any locally-defined permissions tables, procedures, or functions exist, and the list does not include the audit action group SCHEMA_OBJECT_ACCESS_GROUP, this is a finding.

If any of the other audit action groups specified in the WHERE clause are not included in the list, this is a finding.

If the audited_result column is not "FAILURE" or "SUCCESS AND FAILURE" on every row, this is a finding.

Fix Text (F-74043r1_fix)
Where SQL Server Trace is in use, define and enable a trace that captures all auditable events. The script provided in the supplemental file Trace.sql can be used to do this. Add blocks of code to Trace.sql for each custom event class (integers in the range 82-91; the same event class may be used for all such triggers) used in these triggers. Create triggers to raise a custom event on each locally-defined security table that requires tracking of Insert-Update-Delete operations. The examples provided in the supplemental file CustomTraceEvents.sql can serve as the basis for these. Execute Trace.sql Where SQL Server Audit is in use, design and deploy a SQL Server Audit that captures all auditable events. The script provided in the supplemental file Audit.sql can be used for this. Alternatively, to add the necessary data capture to an existing server audit specification, run the script: USE [master]; GO ALTER SERVER AUDIT SPECIFICATION WITH (STATE = OFF); GO ALTER SERVER AUDIT SPECIFICATION ADD (SCHEMA_OBJECT_ACCESS_GROUP); GO ALTER SERVER AUDIT SPECIFICATION WITH (STATE = ON); GO

Fix Text (F-74043r1_fix)

Where SQL Server Trace is in use, define and enable a trace that captures all auditable events. The script provided in the supplemental file Trace.sql can be used to do this.

Add blocks of code to Trace.sql for each custom event class (integers in the range 82-91; the same event class may be used for all such triggers) used in these triggers.

Create triggers to raise a custom event on each locally-defined security table that requires tracking of Insert-Update-Delete operations. The examples provided in the supplemental file CustomTraceEvents.sql can serve as the basis for these.

Execute Trace.sql

Where SQL Server Audit is in use, design and deploy a SQL Server Audit that captures all auditable events. The script provided in the supplemental file Audit.sql can be used for this.

Alternatively, to add the necessary data capture to an existing server audit specification, run the script:
USE [master];
GO
ALTER SERVER AUDIT SPECIFICATION WITH (STATE = OFF);
GO
ALTER SERVER AUDIT SPECIFICATION ADD (SCHEMA_OBJECT_ACCESS_GROUP);
GO
ALTER SERVER AUDIT SPECIFICATION WITH (STATE = ON);
GO