DOCUMENT:Q229441 16-MAY-2002 [winnt] TITLE :Denial of Service Attack with Duplicate Objects Between Sessions PRODUCT :Microsoft Windows NT PROD/VER:winnt:4.0 OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 4.0, Terminal Server Edition ------------------------------------------------------------------------------- SYMPTOMS ======== A possible denial of service attack exists in Windows NT Server 4.0, Terminal Server Edition when objects containing session-specific information are duplicated between sessions. CAUSE ===== Desktop and window station objects are system objects allocated by the object manager in global system memory and are accessible from all sessions. The problem occurs when a handle to a dekstop or window station is opened from one session and duplicated to a program running in another session. RESOLUTION ========== To resolve this problem, obtain the latest service pack for Windows NT Server 4.0, Terminal Server Edition or the individual software update. For information on obtaining the latest service pack, please go to: - http://www.microsoft.com/windows/servicepacks/ -or- - Q152734 How to Obtain the Latest Windows NT Server 4.0 Service Pack For information on obtaining the individual software update, contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web: http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS STATUS ====== Microsoft has confirmed this to be a problem in Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT Server 4.0, Terminal Server Edition Service Pack 4. Additional query words: ====================================================================== Keywords : Technology : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400search kbNTTermServ400 kbNTTermServSearch Version : winnt:4.0 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.