Microsoft has released a patch that eliminates a security vulnerability in Microsoft Windows NT 4.0. The vulnerability can allow a user who is locally logged on to the computer to grant themselves administrator-level privileges.

A flaw in the NTLM Security Support Provider (NTLMSSP) service can potentially allow a non-administrative user to gain administrative control of the computer. To do this, the user needs a valid logon account and the ability to run arbitrary code on the computer.

This vulnerability can be exploited only by a malicious user who can interactively log on to the affected computer; however, it is recommended that unprivileged users not be allowed to interactively log on to business-critical servers like domain controllers, Enterprise Resource Planning (ERP) servers, print and file servers, database servers, and so on. If unprivileged users are not allowed to interactively log on to business-critical servers, business-critical servers are not at risk from this vulnerability and, as a result, the computers that are most likely to be affected by this vulnerability are workstations and Terminal Servers.

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Windows NT 4.0

To resolve this problem, obtain the individual package referenced below or obtain the Windows NT 4.0 Security Rollup Package. For additional information on the SRP, click the article number below to view the article in the Microsoft Knowledge Base: The following file is available for download from the Microsoft Download Center:
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file. The English-language version of this fix should have the following file attributes or later:

   Date        Time   Size    File name     Platform
   -------------------------------------------------
   11/22/2000  3:20p  36,112  Ntlmssps.dll  Intel
				

NOTE: Due to file dependencies, this hotfix requires Microsoft Windows NT 4.0 Service Pack 6a (SP6a).

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Windows NT Server 4.0, Terminal Server Edition

To resolve this problem, either obtain the hotfix referenced in this section or the Windows NT Server 4.0, Terminal Server Edition, Security Rollup Package (SRP). For additional information about the SRP, click the article number below to view the article in the Microsoft Knowledge Base: A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that this article describes. Apply it only to systems that you determine are at risk of attack. Evaluate the computer's physical accessibility, network and Internet connectivity, and other factors to determine the degree of risk to the computer. See the associated Microsoft Security Bulletin (http://www.microsoft.com/technet/security/bulletin/ms01-008.mspx) to help determine the degree of risk. This hotfix may receive additional testing. If the computer is sufficiently at risk, we recommend that you apply this hotfix now.

To resolve this problem immediately, download the hotfix by following the instructions later in this article or contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site: Note In special cases, charges that are ordinarily incurred for support calls may be canceled, if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The following file is available for download from the Microsoft Download Center:
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on secure servers that prevent any unauthorized changes to the file.

The English-language version of this fix should have the following file attributes or later:

   Date        Time    Size    File name     Platform
   --------------------------------------------------
   01/26/2001  09:01p  35,600  Ntlmssps.dll  Intel
				

NOTE: Due to file dependencies, this hotfix requires Microsoft Windows NT Server 4.0, Terminal Server Edition Service Pack 6 (SP6).

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Windows NT Server 4.0

Microsoft has confirmed that this problem may cause a degree of security vulnerability in Microsoft Windows NT 4.0.

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Windows NT Server 4.0, Terminal Server Edition

Microsoft has confirmed that this problem may cause a degree of security vulnerability in Windows NT Server 4.0, Terminal Server Edition.

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For more information about this vulnerability, view the following Microsoft Web site:

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