STIGQter: STIG Summary: MS SQL Server 2016 Instance Security Technical Implementation Guide Version: 2 Release: 3 Benchmark Date: 23 Apr 2021:

The audit information produced by SQL Server must be protected from unauthorized access, modification, and deletion.

DISA Rule

SV-213944r617437_rule

Vulnerability Number

V-213944

Group Title

SRG-APP-000118-DB-000059

Rule Version

SQL6-D0-005900

Severity

CAT II

CCI(s)

• CCI-000162 - The information system protects audit information from unauthorized access.
• CCI-000163 - The information system protects audit information from unauthorized modification.
• CCI-000164 - The information system protects audit information from unauthorized deletion.

Weight

10

Fix Recommendation

Modify audit file permissions to meet the requirement to protect against unauthorized access.

Application event log and security log permissions are covered in the Windows Server STIGs. Be sure to reference these depending on the OS in use.

Navigate to audit folder location(s) using a command prompt or Windows Explorer. Right-click the file and click "Properties".

On the Security tab, modify the security permissions to:
Administrator (read)
Users (none)
Audit Administrator(Full Control)
Auditors group (Read)
SQL Server Service SID OR Service Account (Full Control) [Notes 1, 2]
SQL Server SQL Agent Service SID OR Service Account, if SQL Server Agent is in use. (Read, Execute, Write) [Notes 1, 2]

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Note 1: It is highly advisable to use a separate account for each service. When installing SQL Server in single-server mode, you can opt to have these provisioned for you. These automatically-generated accounts are referred to as virtual accounts. Each virtual account has an equivalent Service SID, with the same name. The installer also creates an equivalent SQL Server login, also with the same name. Applying folder and file permissions to Service SIDs, rather than to domain accounts or local computer accounts, provides tighter control, because these permissions are available only to the specific service when it is running, and not in any other context. (However, when using failover clustering, a domain account must be specified at installation, rather than a virtual account.) For more on this topic, see http://msdn.microsoft.com/en-us/library/ms143504(v=sql.130).aspx.

Note 2: Tips for adding a service SID/virtual account to a folder's permission list.

1) In Windows Explorer, right-click the folder and select "Properties".
2) Select the "Security" tab.
3) Click "Edit".
4) Click "Add".
5) Click "Locations".
6) Select the computer name.
7) Search for the name.
7.a) SQL Server Service
7.a.i) Type "NT SERVICE\MSSQL" and click "Check Names". (What you have just typed in is the first 16 characters of the name. At least one character must follow "NT SERVICE\"; you will be presented with a list of all matches. If you have typed in the full, correct name, step 7.a.ii is bypassed.)
7.a.ii) Select the "MSSQL$" user and click "OK".
7.b) SQL Agent Service
7.b.i) Type "NT SERVICE\SQL" and click "Check Names".
7.b.ii) Select the "SQLAgent$" user and click "OK".
8) Click "OK".
9) Permission like a normal user from here.

Check Contents

If the database is setup to write audit logs using APPLICATION or SECURITY event logs rather than writing to a file, this is N/A.

Obtain the SQL Server audit file location(s) by running the following SQL script:

SELECT log_file_path AS "Audit Path"
FROM sys.server_file_audits

For each audit, the path column will give the location of the file.

Verify that all audit files have the correct permissions by doing the following for each audit file: Navigate to audit folder location(s) using a command prompt or Windows Explorer.

Right-click the file/folder and click "Properties". On the "Security" tab, verify that at most the following permissions are applied:

Administrator (read)
Users (none)
Audit Administrator (Full Control)
Auditors group (Read)
SQL Server Service SID OR Service Account (Full Control)
SQL Server SQL Agent Service SID OR Service Account, if SQL Server Agent is in use. (Read, Execute, Write)

If any less restrictive permissions are present (and not specifically justified and approved), this is a finding.

Vulnerability Number

V-213944

Documentable

False

Rule Version

SQL6-D0-005900

Severity Override Guidance

If the database is setup to write audit logs using APPLICATION or SECURITY event logs rather than writing to a file, this is N/A.

Obtain the SQL Server audit file location(s) by running the following SQL script:

SELECT log_file_path AS "Audit Path"
FROM sys.server_file_audits

For each audit, the path column will give the location of the file.

Verify that all audit files have the correct permissions by doing the following for each audit file: Navigate to audit folder location(s) using a command prompt or Windows Explorer.

Right-click the file/folder and click "Properties". On the "Security" tab, verify that at most the following permissions are applied:

Administrator (read)
Users (none)
Audit Administrator (Full Control)
Auditors group (Read)
SQL Server Service SID OR Service Account (Full Control)
SQL Server SQL Agent Service SID OR Service Account, if SQL Server Agent is in use. (Read, Execute, Write)

If any less restrictive permissions are present (and not specifically justified and approved), this is a finding.

Check Content Reference

M

Target Key

3993

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