Article ID: 307454 - View products that this article applies to.
This article was previously published under Q307454
TECHNICAL UPDATES
  • May 11, 2004: This article was updated to provide information about a new security update for Windows NT Server 4.0, Terminal Server Edition.
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SYMPTOMS

A denial of service vulnerability exists in Terminal Services in Windows 2000 and in Windows NT Server 4.0, Terminal Server Edition. An attacker may use this vulnerability to cause a Windows 2000 or a Windows NT 4.0 terminal server to fail. The server may be restarted without incident, but any work that was in progress at the time of the failure will be lost.

Mitigating factors

  • There is no capability to breach the security of a terminal server session by using this vulnerability, or to add, change, or delete data on the server. It is a denial of service vulnerability only.
  • The specific sequence of data packets that are involved in this vulnerability cannot be generated as part of a legitimate terminal server session.
Important When you try to connect to RDP-TCP sessions after you apply the October 18, 2001 version of the Windows 2000 update, you may receive the following error message:
Terminal service client disconnected
The client did not connect to the terminal server. The server may be too busy. Please try connecting later.
To resolve this problem, apply the October 22, 2001 version of the Windows 2000 update. See the "Resolution" section for information about how to obtain the latest update.

This problem does not occur with the Windows NT Server 4.0, Terminal Services Edition update.

CAUSE

This vulnerability occurs because Windows NT Server 4.0, Terminal Server Edition and Terminal Services in Windows 2000 fail when they receive a particular series of packets over a Remote Desktop Protocol (RDP) connection.

RESOLUTION

Windows 2000

To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
260910 How to obtain the latest Windows 2000 service pack
The resolution for this problem is also included in Windows 2000 Security Rollup Package 1 (SRP1). For additional information about SRP1, click the following article number to view the article in the Microsoft Knowledge Base:
311401 Windows 2000 Security Rollup Package 1 (SR about SRP1), January 2002
The following files are available for download from the Microsoft Download Center:
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English Language Version

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Chinese (Simplified) Language Version

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Chinese (Traditional) Language Version

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Hungarian Language Version

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Italian Language Version

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Japanese Language Version

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Korean Language Version

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Norwegian Language Version

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Polish Language Version

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Portuguese (Brazilian) Language Version

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Russian Language Version

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Turkish Language Version

Release Date: October 22, 2001

For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to Obtain Microsoft Support Files from Online Services
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 version of this hotfix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
   Date         Time   Version           Size     File name
   --------------------------------------------------------------------
   19-Oct-2001  14:40  5.0.2195.3895     125,712  Icaapi.dll       
   19-Oct-2001  14:42  5.0.2195.4527     107,280  Instrdp5.dll     
   19-Jul-2001  20:39  5.0.2195.3895      93,456  Licmgr.exe       
   28-Sep-2001  18:30  5.0.2195.4435     330,000  Lserver.exe      
   19-Oct-2001  14:40  5.0.2195.3895      26,384  Mstlsapi.dll
   19-Oct-2001  14:42  5.0.2195.4527      89,080  Rdpwd.sys     128-bit
   19-Oct-2001  14:42  5.0.2195.4527      89,048  Rdpwd.sys      56-bit
   18-Oct-2001  21:22  5.0.2195.4527     100,248  Rdpwsx.dll       
   19-Jul-2001  20:39  5.0.2195.3895     141,584  Termsrv.exe      
   19-Oct-2001  14:40  5.0.2195.3895      23,312  Tls236.dll       
				
Note Because of file dependencies, this update requires Windows 2000 Service Pack 1 or Service Pack 2.

Windows NT Server 4.0, Terminal Server Edition

The following file is available for download from the Microsoft Download Center:
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Download the WindowsNT4TerminalServer-KB307454-x86-ENU.EXE package now. Release Date: May 11, 2004

For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to Obtain Microsoft Support Files from Online Services
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 version of this hotfix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
   Date         Time   Version            Size    File name
   --------------------------------------------------------------
   14-Apr-2004  10:08  4.0.1381.33564     70,928  Icaapi.dll       
   14-Apr-2004  10:10  4.0.1381.33564     91,608  Rdpwd.sys
   15-Feb-2002  21:27  4.0.1381.33528     41,880  Rdpwsx.dll       

The English version of the original security update (Q307454i.exe) was released on October 19, 2001. The original update has the file attributes that are listed in the following table.
   Date         Time   Version            Size    File name
   ---------------------------------------------------------
   31-Jul-2001  11:22  4.0.1381.33478     61,712  Icaapi.dll
   08-Oct-2001  16:16  4.0.1381.33478     91,512  Rdpwd.sys
   08-Oct-2001  16:36  4.0.1381.33478     41,880  Rdpwsx.dll
				
Note Because of file dependencies, this update requires Windows NT Server 4.0, Terminal Server Edition Service Pack 6.

STATUS

Windows 2000

Microsoft has confirmed that this problem may cause a degree of security vulnerability in Microsoft Windows 2000. This problem was first corrected in Windows 2000 Service Pack 3.

Windows NT Server 4.0, Terminal Server Edition

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

MORE INFORMATION

For more information about this vulnerability, visit the following Microsoft Web site:
http://www.microsoft.com/technet/security/bulletin/MS01-052.mspx
For additional information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the following article number to view the article in the Microsoft Knowledge Base:
265173 The Datacenter Program and Windows 2000 Datacenter Server product
For additional information about how to install multiple hotfixes with only one reboot, click the following article number to view the article in the Microsoft Knowledge Base:
296861 How to install multiple Windows updates or hotfixes with only one reboot

Properties

Article ID: 307454 - Last Review: February 20, 2007 - Revision: 5.2
APPLIES TO
  • Microsoft Windows 2000 Service Pack 1
  • Microsoft Windows 2000 Service Pack 2
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows NT Server 4.0, Terminal Server Edition Service Pack 4
  • Microsoft Windows NT Server 4.0, Terminal Server Edition Service Pack 5
  • Microsoft Windows NT Server 4.0, Terminal Server Edition Service Pack 6
Keywords: 
kbbug kbfix kbwin2000presp3fix kbsecvulnerability kbqfe kbwin2000sp3fix kbenv kbnetwork kbsecurity kbsecbulletin kbtermserv kbsechack kbhotfixserver KB307454

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