SQL4-00-036850 - Trace or Audit records must be generated when unsuccessful attempts to modify categorized information (e.g., classification levels/security levels) occur - Event ID 91

Information

Changes in categorized information must be tracked. Without an audit trail, unauthorized access to protected data could go undetected.

For detailed information on categorizing information, refer to FIPS Publication 199, Standards for Security Categorization of Federal Information and Information Systems, and FIPS Publication 200, Minimum Security Requirements for Federal Information and Information Systems.

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.

Since Trace does not provide for tracking SELECT statements, it is necessary to provide that part of the tracking at the application level. Because of this, it may also be appropriate to audit UPDATE actions at the application level. However, to capture all UPDATEs, whether they come from the application or bypass it, the Trace must be configured to cover them.

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 for UPDATEs on each table holding categorized information. 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 Database Audit v1r7

Category: AUDIT AND ACCOUNTABILITY

Plugin: MS_SQLDB

Control ID: 7b214a6f30a7359fa9c23d782d7ab7c01e641da2b42365213539417c84f8d8b0

Detections

Analytics

SQL4-00-036850 - Trace or Audit records must be generated when unsuccessful attempts to modify categorized information (e.g., classification levels/security levels) occur - Event ID 91

Information

Solution

See Also

Item Details