SQL Server must protect its audit features from unauthorized access.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-79157	SQL6-D0-006200	SV-93863r1_rule		Medium

Description
Protecting audit data also includes identifying and protecting the tools used to view and manipulate log data. Depending upon the log format and application, system and application log tools may provide the only means to manipulate and manage application and system log data. It is, therefore, imperative that access to audit tools be controlled and protected from unauthorized access. Applications providing tools to interface with audit data will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys in order make access decisions regarding the access to audit tools. SQL Server is an application that does provide access to audit data. Audit tools include, but are not limited to, OS-provided audit tools, vendor-provided audit tools, and open source audit tools needed to successfully view and manipulate audit information system activity and records. If an attacker were to gain access to audit tools, he could analyze audit logs for system weaknesses or weaknesses in the auditing itself. An attacker could also manipulate logs to hide evidence of malicious activity.

Description

Protecting audit data also includes identifying and protecting the tools used to view and manipulate log data. Depending upon the log format and application, system and application log tools may provide the only means to manipulate and manage application and system log data. It is, therefore, imperative that access to audit tools be controlled and protected from unauthorized access. Applications providing tools to interface with audit data will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys in order make access decisions regarding the access to audit tools. SQL Server is an application that does provide access to audit data. Audit tools include, but are not limited to, OS-provided audit tools, vendor-provided audit tools, and open source audit tools needed to successfully view and manipulate audit information system activity and records. If an attacker were to gain access to audit tools, he could analyze audit logs for system weaknesses or weaknesses in the auditing itself. An attacker could also manipulate logs to hide evidence of malicious activity.

STIG	Date
MS SQL Server 2016 Instance Security Technical Implementation Guide	2018-03-09

Details

Check Text ( C-78749r1_chk )
Check the server documentation for a list of approved users with access to SQL Server Audits. To create, alter, or drop a server audit, principals require the ALTER ANY SERVER AUDIT or the CONTROL SERVER permission. To view an Audit log requires the CONTROL SERVER permission. To use Profiler, ALTER TRACE is required. Review the SQL Server permissions granted to principals. Look for permissions ALTER ANY SERVER AUDIT, ALTER ANY DATABASE AUDIT, CONTROL SERVER, ALTER TRACE: SELECT login.name, perm.permission_name, perm.state_desc FROM sys.server_permissions perm JOIN sys.server_principals login ON perm.grantee_principal_id = login.principal_id WHERE permission_name in ('CONTROL SERVER', 'ALTER ANY DATABASE AUDIT', 'ALTER ANY SERVER AUDIT','ALTER TRACE') and login.name not like '##MS_%'; If unauthorized accounts have these privileges, this is a findinglogin.name not like '##MS_%'; If unauthorized accounts have these privileges, this is a finding.

Check Text ( C-78749r1_chk )

Check the server documentation for a list of approved users with access to SQL Server Audits.

To create, alter, or drop a server audit, principals require the ALTER ANY SERVER AUDIT or the CONTROL SERVER permission. To view an Audit log requires the CONTROL SERVER permission. To use Profiler, ALTER TRACE is required.

Review the SQL Server permissions granted to principals. Look for permissions ALTER ANY SERVER AUDIT, ALTER ANY DATABASE AUDIT, CONTROL SERVER, ALTER TRACE:

SELECT login.name, perm.permission_name, perm.state_desc
FROM sys.server_permissions perm
JOIN sys.server_principals login
ON perm.grantee_principal_id = login.principal_id
WHERE permission_name in ('CONTROL SERVER', 'ALTER ANY DATABASE AUDIT', 'ALTER ANY SERVER AUDIT','ALTER TRACE')
and login.name not like '##MS_%';

If unauthorized accounts have these privileges, this is a findinglogin.name not like '##MS_%';

If unauthorized accounts have these privileges, this is a finding.

Fix Text (F-85909r1_fix)
Remove audit-related permissions from individuals and roles not authorized to have them. USE master; DENY [ALTER ANY SERVER AUDIT] TO [User]; GO