Microsoft SQL Server
TMA-MSSQL-2.12
Ensure 'Hide Instance' option is set to 'Yes' for Production SQL Server instances
Description
Non-clustered SQL Server instances within production environments should be designated as hidden to prevent advertisement by the SQL Server Browser service. Applies to production instances; reads HideInstance through xp_instance_regread (1 = hidden). Default: By default, this option is disabled (0). Runs one sqlcmd query with its defaults (Windows authentication to the local default instance); set SQLCMDSERVER, SQLCMDUSER and SQLCMDPASSWORD for another instance or SQL authentication. Needs VIEW SERVER STATE / sysadmin-level read access.
How it is checked
Audit method: SQL query
sqlcmd -b -h -1 -W -Q "SET NOCOUNT ON; DECLARE @v int; EXEC master.sys.xp_instance_regread @rootkey = N'HKEY_LOCAL_MACHINE', @key = N'SOFTWARE\Microsoft\Microsoft SQL Server\MSSQLServer\SuperSocketNetLib', @value_name = N'HideInstance', @value = @v OUTPUT; SELECT ISNULL(@v, 0);"- Expected output
1
How it is fixed
Fix method: Guidance or infrastructure patch
Perform either the GUI or T-SQL method shown: GUI Method 1. In SQL Server Configuration Manager, expand SQL Server Network Configuration, right-click Protocols for <InstanceName>, and then select Properties. 2. On the Flags tab, in the Hide Instance box, select Yes, and then click OK to close the dialog box. The change takes effect immediately for new connections. T-SQL Method Execute the following T-SQL to remediate: EXEC master.sys.xp_instance_regwrite @rootkey = N'HKEY_LOCAL_MACHINE', @key = N'SOFTWARE\Microsoft\Microsoft SQL Server\MSSQLServer\SuperSocketNetLib', @value_name = N'HideInstance', @type = N'REG_DWORD', @value = 1;
Properties
- Operating systems
- Any
- Tags
- mssqldatabasenetwork
- Reference
- CIS Microsoft SQL Server 2025 Benchmark v1.0.0 - 2.12 Ensure 'Hide Instance' option is set to 'Yes' for Production SQL Server instances
Check this host
Run this on a machine you are allowed to audit. The scan is read-only.
tmaegis scan --target mssql