Azure SQL Managed Instance must enforce access restrictions associated with changes to the configuration of the instance.

Failure to provide logical access restrictions associated with changes to configuration may have significant effects on the overall security of the system.

When dealing with access restrictions pertaining to change control, it must be noted that any changes to the hardware, software, and/or firmware components of the information system can potentially have significant effects on the overall security of the system.

Accordingly, only qualified and authorized individuals must be allowed to obtain access to system components for the purposes of initiating changes, including upgrades and modifications.

Obtain a list of logins who have privileged permissions and role memberships in SQL.

Execute the following query to obtain a list of logins and roles and their respective permissions assignment:

SELECT p.name AS Principal, p.type_desc AS Type, sp.permission_name AS Permission, sp.state_desc AS State FROM sys.server_principals p INNER JOIN sys.server_permissions sp ON p.principal_id = sp.grantee_principal_id WHERE sp.permission_name = 'CONTROL SERVER' OR sp.state = 'W'

Execute the following query to obtain a list of logins and their role memberships.

SELECT m.name AS Member, m.type_desc AS Type, r.name AS Role FROM sys.server_principals m INNER JOIN sys.server_role_members rm ON m.principal_id = rm.member_principal_id INNER JOIN sys.server_principals r ON rm.role_principal_id = r.principal_id WHERE r.name IN ('sysadmin','securityadmin','serveradmin')

Check the server documentation to verify the logins and roles returned are authorized. If the logins and/or roles are not documented and authorized, this is a finding.

Revoke unauthorized permissions from principals: https://learn.microsoft.com/en-us/sql/t-sql/statements/revoke-server-permissions-transact-sql?view=azuresqldb-mi-current

Remove unauthorized logins from roles:

ALTER SERVER ROLE DROP MEMBER login;

Refer to: https://learn.microsoft.com/en-us/sql/t-sql/statements/alter-server-role-transact-sql?view=azuresqldb-mi-current