DOCUMENT:Q277910 08-MAY-2002 [winnt] TITLE :Patch Available for "Terminal Server Login Buffer Overflow" PRODUCT :Microsoft Windows NT PROD/VER::4.0 OPER/SYS: KEYWORDS:kbSecurity kbWinNT400PreSP7Fix kbgraphxlinkcritical KbSECVulnerability KbSECHack ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 4.0, Terminal Server Edition ------------------------------------------------------------------------------- SYMPTOMS ======== Microsoft has released a patch that eliminates a security vulnerability in Microsoft Windows NT Server 4.0, Terminal Server Edition. An unchecked buffer in the Terminal Server logon prompt could allow a malicious user to cause the Terminal Server-based server to run arbitrary code. The ability to run arbitrary code could allow the malicious user to add, change, or delete data, run code already on the server, or upload new code to the server and run it. The malicious user would not need to successfully log on to the Terminal Server-based server to initiate this attack. This vulnerability could be exploited remotely if connection requests are not filtered. By default, Terminal Server listens on TCP port 3389. You should block this port at the firewall or router if Terminal Server access from the Internet is not required. RESOLUTION ========== 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: Q317636 Windows NT Server 4.0, Terminal Server Edition, Security Rollup Package The following file is available for download from the Microsoft Download Center: DownloadDownload Q277910i.exe now (http://www.microsoft.com/Downloads/Release.asp?ReleaseID=25565) For additional information about how to download Microsoft Support files, click the article number below to view the article in the Microsoft Knowledge Base: Q119591 How to Obtain Microsoft Support Files from Online Services Microsoft used the most current virus detection software available on the date of posting to scan this file for viruses. After it is posted, the file is housed on secure servers that prevent any unauthorized changes to the file. The English version of this fix should have the following file attributes or later: Date Time Size File name Platform ------------------------------------------------ 10/03/2000 06:21p 42,768 Regapi.dll Intel STATUS ====== Microsoft has confirmed that this problem could result in some degree of security vulnerability in Windows NT Server 4.0, Terminal Server Edition. MORE INFORMATION ================ For related information about this problem, please visit the following Microsoft Web site: http://www.microsoft.com/technet/security/bulletin/ms00-087.asp Additional query words: security_patch kbtsesrp ====================================================================== Keywords : kbSecurity kbWinNT400PreSP7Fix kbgraphxlinkcritical KbSECVulnerability KbSECHack Technology : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400search kbNTTermServ400 kbNTTermServSearch Version : :4.0 Hardware : ALPHA x86 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2002.