SQL4-00-035700 - SQL Server must produce Trace or Audit records when unsuccessful attempts to access security objects occur - Event ID 91

Information

Changes to the security configuration must be tracked. To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

This requirement applies to situations where security data is retrieved or modified via data manipulation operations, as opposed to via SQL Server's built-in security functionality (GRANT, REVOKE, DENY, ALTER [SERVER] ROLE ... ADD/DROP MEMBER ..., etc.).

In SQL Server, types of access include, but are not necessarily limited to:
SELECT
INSERT
UPDATE
DELETE
EXECUTE

Since the system views are read-only, and the underlying tables are kept hidden by SQL Server, the Insert, Update and Delete cases are relevant only where the database includes user-defined tables to support additional security functionality.

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. Note also that Trace does not support auditing of SELECT statements, whereas Audit does.

Use of SQL Server Audit's SCHEMA_OBJECT_ACCESS_GROUP causes capture of all accesses, successful and otherwise, to all schema-scoped objects. The [Succeeded] column in the audit output indicates the success or failure of the attempted action. Be aware, however, that it may report True in some cases where one would intuitively expect False. For example, SELECT 1/0 FROM SYS.ALL_OBJECTS will appear in the audit trail as successful, if the user has permission to perform that action, even though it contains an invalid expression. Some other actions that one would consider failures (such as selecting from a table that does not exist) may not appear at all.

Solution

Where SQL Server Trace is in use, create triggers to raise a custom event on each 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.

Add a block of code to the supplemental file 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. Execute Trace.sql.

If SQL Server Audit is in use, design and deploy an Audit that captures all auditable events and data items. The script provided in the supplemental file Audit.sql can be used as the basis for this. Supplement the standard audit data as necessary, using Extended Events and/or triggers.

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

Item Details

Audit Name: DISA STIG SQL Server 2014 Instance DB Audit v2r4

Category: AUDIT AND ACCOUNTABILITY

Plugin: MS_SQLDB

Control ID: 4ecba45d4b356cd8aaaf9f9d1439e469ae38b5c51a089d16a740038f3c3ff63a

Detections

Analytics

SQL4-00-035700 - SQL Server must produce Trace or Audit records when unsuccessful attempts to access security objects occur - Event ID 91

Information

Solution

See Also

Item Details