ID
OM-BP-0017
Status
| Status | ||||
|---|---|---|---|---|
|
Best Practice
Remove orphans in systems requiring the declaration of user accounts in multiple sub-systems.
Rationale
In some systems, user accounts must be declared in multiple sub-systems. When accesses must be removed, for example as part of the mover and leaver processes, it may sound attractive to deactivate or remove the user accounts in only one of the sub-systems. This leaves orphan user accounts in the system. Such orphan user accounts constitute an extension of the attack surface as they may be leveraged to gain unauthorized access to the system, they thus represent a risk. See https://open-measure.atlassian.net/wiki/spaces/DIC/pages/1062207530/Orphan+Account+Dictionary+Entry#Definition-3-IAM.
To mitigate this risk, remove orphaned users systematically.
Bad Practices
Do not identify systems where user accounts must be declared in multiple sub-systems
In such systems, do not remove orphaned users
Implementation Details
- Provide a sample naming convention for a typical organization
- Identify systems where user accounts are declared in multiple sub-systems.
- For these systems, document the account removal procedure by expressly mentioning the removal of user accounts in all sub-systems.
- Whenever feasible, automate the account removal process.
Quotes
4.3 Drop Orphaned Users From SQL Server Databases (Scored)
Profile Applicability:
Level 1 - SQL Server 2008.x
Description:
A database user for which the corresponding SQL Server login is undefined or is incorrectly defined on a server instance cannot log in to the instance and is referred to as orphaned and should be removed.
Rationale:
Orphan users should be removed to avoid potential misuse of those broken users in any way.
Audit:
Run the following T-SQL query to identify orphan users:
EXEC sp_change_users_login @Action='Report';Remediation:
Run the following T-SQL query to remove an orphan user:
DROP USER <username>;References:
1. http://msdn.microsoft.com/en-us/library/ms175475(v=sql.100).aspx
2. http://msdn.microsoft.com/en-us/library/ms175475(v=sql.105).aspx
(CIS, 2012 , p. 42)
Bibliography
Related Best Practices
N/A