SBS Allows Unauthorized Shutdown from Logon Prompt

• Microsoft BackOffice Small Business Server versions 4.0, 4.0a

SYMPTOMS

The Shut Down button on the intial logon prompt is disabled by default on retail Windows NT Server installations. This is to provide additional security by forcing an authorized user to log on locally to the server to be able to perform a shutdown.

In BackOffice Small Business Server (SBS), the Shut Down button is enabled by default, which allows anyone to perform a soft shut down of the server without being validated by the server.

RESOLUTION

To work around this problem, use either of the following methods:

• Method 1
  
  Modify the funtionality through a registry setting.
  
  WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.
  
  For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).
  
  
  1. Run Registry Editor (Regedt32.exe).
  
  
  
  2. From the HKEY_LOCAL_MACHINE subtree, go to the following key:

     \SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Winlogon

  
  
  
  3. Delete the ShutdownWithoutLogon value.
     
     NOTE: It is incorrectly listed with a value type of REG_DWORD and should be REG_SZ.
  
  
  
  4. Select the \Winlogon key.
  
  
  
  5. Add the following value to the key:

     Value Name: ShutDownWithoutLogon
     Data Type: REG_SZ
     String: 0=Disabled; 1=Enabled

  
  
  
  6. Close the registry.
  
  
  
  7. Log off for changes to take place.
  
  
  
  



• Method 2
  
  
  1. Log on locally to the SBS server with a valid account.
  
  
  
  2. Press CTRL+ALT+DEL to bring up the Windows NT Security dialog box
  
  
  
  3. Select Lock Workstation.
  
  
  
  
  
  This locks the server so that only the logged on individual or an Administrator can unlock it. There is no option to Shut Down the server from this logon prompt.

MORE INFORMATION

For additional information, please see the following article(s) in the Microsoft Knowledge Base:

Q114817 No Shutdown Button in Windows NT Server Welcome Screen

Additional query words: smallbiz

Keywords :
Version : winnt:4.0,4.0a
Platform : winnt
Issue type : kbprb