Windows NT LAN Manager Version 3 Client with First Logon Prevents Subsequent Logon Activity

• Microsoft Windows NT Server version 4.0
• Microsoft Windows NT Workstation version 4.0
• Microsoft Windows NT Server, Enterprise Edition version 4.0

SYMPTOMS

When a client uses Windows NT LAN Manager version 2 authentication (also known as NTLMv2) that is configured with the LmCompatibilityLevel setting to 3 or higher to make a connection to a server running Windows NT 4.0 before a console user has logged on interactively or some other client has performed network logon using LAN Manager or NTLMv1 authentication, one of the following symptoms may occur on the server:

• The server may generate an "access violation" error message, possibly relating to the LSASS service. This may occur on both the server and the client during startup, especially during periods of heavy network logon traffic.



• The domain name field may not appear on the logon screen of the server even though the user name and password fields do. You may not be able to log on to the domain because this indicates that the domain controller cannot be found.



• Your logon attempt may not work, and you may receive the following error message:




The system cannot log you on (C0000037). Please try again or consult your system administrator.

CAUSE

This behavior occurs because the Windows NT LAN Manager version 2 (level 3+) logon is received and processed by the server before the NlSamInitialize function is called, causing an "Access violation" error message. Also, at this time Lsass.exe generates a "STATUS_PORT_DISCONNECTED" error message, which prevents subsequent logon attempts from succeeding.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0. For additional information, please see the following article in the Microsoft Knowledge Base:

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

STATUS

Microsoft has confirmed this to be a problem in Windows NT 4.0. This problem was first corrected in Windows NT 4.0 Service Pack 6.

MORE INFORMATION

Windows NT 4.0 supports Windows NT challenge/response (or Windows NT LAN Manager challenge/response) as a method of authentication, along with Basic Authentication and Anonymous Access. Microsoft has developed an enhancement to NTLM called Windows NT LAN Manager version 2 which uses a 128-bit password-derived key and significantly improves session security mechanisms.

For more information about Windows NT LAN Manager version 2, please click the article number below to view the article in the Microsoft Knowledge Base:

Q147706 How to Disable LM Authentication on Windows NT

• When a server service that runs using a user account starts before the first non-anonymous logon.



• When a user interactively logs on to the server console before the first non-anonymous logon occurred.



• When a client computer is not configured to send Windows NT LAN Manager version 2 only (level 3) as the first non-anonymous logon

Additional query words: ntlmv2 ntlm invalid handle invalid_handle 6

Keywords : kberrmsg kbnetwork ntdomain ntsecurity ntsp kbbug4.00 kbfix4.00 NT4SP6Fix
Version : winnt:4.0
Platform : winnt
Issue type : kbbug