Can No Longer Access the Registry with Null Sessions

• Microsoft Windows NT Server version 4.0
• Microsoft Windows NT Workstation version 4.0

SYMPTOMS

After you apply the security hotfix (Sec-fix) or Windows NT 4.0 Service Pack 3, which includes this hotfix, applications that use null sessions may no longer work properly.

For example, after you apply the security hotfix to a Windows NT computer running Cheyenne ARCServe 6.0, you may receive the following error message when you attempt to schedule a job (for example, local, remote, backup, and restore):

   User doesn't have enough rights to do this
   EC=5

CAUSE

The updated security modules for Windows NT no longer permit null sessions to access the Windows NT registry.

RESOLUTION

Perform the following steps to resolve this problem:

WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

1. Run Registry Editor (Regedt32.exe).

2. Go to the following key in the registry:

         HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\
         LanmanServer\Parameters\
   

3. Add "winreg" (without the quotation marks) to the NullSessionPipes entry.

4. Restart your computer.

MORE INFORMATION

For more information on the security hotfix (Sec-fix,) please see the following article(s) in the Microsoft Knowledge Base:

   ARTICLE-ID: Q143474
   TITLE     : Restricting Information Available to Anonymous Logon Users

   ARTICLE-ID: Q143475
   TITLE     : Windows NT System Key Permits Strong Encryption of the SAM

   ARTICLE-ID: Q161372
   TITLE     : How to Enable SMB Signing in Service Pack 3