The Database Master Key should be encrypted by the Service Master Key where required.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-15161	DM6179-SQLServer9	SV-23861r2_rule	IAKM-1 IAKM-2 IAKM-3	Medium

Description
Protection of the Database Master Key is necessary to protect the confidentiality of sensitive data. When encrypted by the Service Master Key, SYSADMINs may access and use the key to view sensitive data that they are not authorized to view. Where alternate encryption means are not feasible, encryption by the Service Master Key may be necessary. To help protect sensitive data from unauthorized access by DBA's, mitigations may be in order. Mitigations may include automatic alerts or other audit events when the database master key is accessed outside of the application or by a DBA account.

Description

Protection of the Database Master Key is necessary to protect the confidentiality of sensitive data. When encrypted by the Service Master Key, SYSADMINs may access and use the key to view sensitive data that they are not authorized to view. Where alternate encryption means are not feasible, encryption by the Service Master Key may be necessary. To help protect sensitive data from unauthorized access by DBA's, mitigations may be in order. Mitigations may include automatic alerts or other audit events when the database master key is accessed outside of the application or by a DBA account.

STIG	Date
Microsoft SQL Server 2005 Database Security Technical Implementation Guide	2015-06-16

Details

Check Text ( C-13835r2_chk )
From the query prompt: SELECT name FROM [master].sys.databases WHERE is_master_key_encrypted_by_server = 1 AND owner_sid <> 1 AND state = 0 If no databases are returned, this is Not a Finding. For any databases returned, verify in the System Security Plan that encryption of the Database Master Key using the Service Master Key is acceptable and approved by the Information Owner and the encrypted data does not require additional protections to deter or detect DBA access. If not approved, this is a Finding. If approved and additional protections are required, then verify that the additional requirements are in place in accordance with the System Security Plan. These may include additional auditing on access of the Database Master Key with alerts or other automated monitoring. If the additional requirements are not in place, this is a Finding.

Check Text ( C-13835r2_chk )

From the query prompt:

SELECT name
FROM [master].sys.databases
WHERE is_master_key_encrypted_by_server = 1
AND owner_sid <> 1
AND state = 0

If no databases are returned, this is Not a Finding.

For any databases returned, verify in the System Security Plan that encryption of the Database Master Key using the Service Master Key is acceptable and approved by the Information Owner and the encrypted data does not require additional protections to deter or detect DBA access. If not approved, this is a Finding.

If approved and additional protections are required, then verify that the additional requirements are in place in accordance with the System Security Plan. These may include additional auditing on access of the Database Master Key with alerts or other automated monitoring.

If the additional requirements are not in place, this is a Finding.

Fix Text (F-14856r1_fix)
Where possible, encrypt the Database Master Key with a password known only to the application administrator. Where not possible, configure additional audit events or alerts to detect unauthorized access to the database master key by users not authorized to view sensitive data.