Detections
Analytics

SQL4-00-036300 - SQL Server must generate Trace or Audit records when unsuccessful attempts to modify privileges/permissions via locally-defined security objects occur - SCHEMA_OBJECT_ACCESS_GROUP

Information

Failed attempts to change the permissions, privileges, and roles granted to users and roles must be tracked. Without an audit trail, unauthorized attempts to elevate or restrict privileges could go undetected.

In SQL Server, there is no distinction between modification of permissions and granting or dropping them. However, native SQL Server security functionality may be supplemented with application-specific tables and logic, in which case the following actions on these tables and procedures/triggers/functions are also relevant:
UPDATE
EXECUTE

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.

Use of SQL Server Audit's SCHEMA_OBJECT_ACCESS_GROUP causes capture of all accesses, successful and otherwise, to the system views (and all other 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, 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 <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

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_MS_SQL_Server_2014_Y24M07_STIG.zip

Item Details

Category: AUDIT AND ACCOUNTABILITY

References: 800-53|AU-12c., CAT|II, CCI|CCI-000172, Rule-ID|SV-213793r961800_rule, STIG-ID|SQL4-00-036300, STIG-Legacy|SV-81909, STIG-Legacy|V-67419, Vuln-ID|V-213793

Plugin: MS_SQLDB

Control ID: 5354637dc042e760c0b84ccf2a31b474020cd2ba7e7e549c393ba430a15a4738