---------- Forwarded message ---------- Date: Fri, 20 Nov 1998 15:58:59 -0800 From: Microsoft Product Security <secnotifat_private> To: MICROSOFT_SECURITYat_private Subject: Microsoft Security Bulletin (MS98-017) The following is a Security Bulletin from the Microsoft Product Security Notification Service. Please do not reply to this message, as it was sent from an unattended mailbox. ******************************** Microsoft Security Bulletin (MS98-017) -------------------------------------- Patch Available for "Named Pipes Over RPC" Issue Originally Posted: November 19, 1998 Summary ======= Microsoft has released a patch that fixes a vulnerability in the way Microsoft (r) Windows NT (r) 4.0 handles named pipes over the Remote Procedure Call (RPC) services. An attacker could create a denial of service situation on a Windows NT 4.0 system by opening multiple named pipe connections to RPC services and sending random data. A fully supported fix for this problem is available. As detailed below in What Customers Should Do, Microsoft recommends that customers evaluate the risk that this vulnerability poses to their systems and apply the patch if appropriate. Issue ===== The underlying problem is the way that Windows NT 4.0 attempts to shut down invalid named pipe RPC connections. An attacker could exploit this problem to create a denial of service condition by opening multiple named pipe connections and sending random data. When the RPC service attempts to close the invalid connections, the service consumes all CPU resources and memory use grows considerably, which may result in the system hanging. This is a denial of service vulnerability only; there is no risk of compromise or loss of data from the attacked system. Different attack programs may target different system services. Two of the services typically targeted are the SPOOLSS and LSASS system service processes. Affected Software Versions ========================== - Microsoft Windows NT Workstation 4.0 - Microsoft Windows NT Server 4.0 - Microsoft Windows NT Server 4.0, Enterprise Edition - Microsoft Windows NT Server 4.0, Terminal Server Edition What Microsoft is Doing ======================= On November 19 Microsoft released a patch that fixes the problem identified. This patch is available for download from the sites listed below. Microsoft has sent this security bulletin to customers subscribing to the Microsoft Product Security Notification Service (see http://www.microsoft.com/security/services/bulletin.asp for more information about this free customer service). Microsoft has published the following Knowledge Base (KB) articles on this issue: - Microsoft Knowledge Base (KB) article Q195733, Denial of Service in Applications Using Named Pipes Over RPC http://support.microsoft.com/support/kb/articles/q195/7/33.asp (Note: It might take 24 hours from the original posting of this bulletin for the updated KB article to be visible in the Web-based Knowledge Base.) Microsoft has posted hot fixes to address this problem: - Fix for X86 version of Microsoft Windows NT Workstation 4.0, Microsoft Windows NT Server 4.0, Microsoft Windows NT Server 4.0, Enterprise Edition ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes /usa/NT40/hotfixes-postSP4/nprpc-fix/nprpcfxi.exe (Note: the above URL has been wrapped for readability) - Fix for Alpha version of Microsoft Windows NT Workstation 4.0, Microsoft Windows NT Server 4.0, Microsoft Windows NT Server 4.0, Enterprise Edition ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes /usa/NT40/hotfixes-postSP4/nprpc-fix/nprpcfxa.exe (Note: the above URL has been wrapped for readability) - Fix for Microsoft Windows NT Server 4.0, Terminal Server Edition - This fix will be released shortly. When it is available, http://www.microsoft.com/security will carry an announcement that provides the location of the fix. What customers should do ======================== The patch for this vulnerability is fully supported. However, it has not been fully regression tested and should only be applied to systems determined to be at risk of attack. A fully regression-tested version of the patch will be available as part of the next Windows NT service pack. Microsoft recommends that customers evaluate the degree of risk that this vulnerability poses to their systems, based on physical accessibility, network and Internet connectivity, and other factors, and determine whether the appropriate course of action is to apply the patch or wait for the next service pack. More Information ================ Please see the following references for more information related to this issue. - Microsoft Security Bulletin 98-017, Patch Available for Named Pipes Transport Issue (the Web-posted version of this bulletin), http://www.microsoft.com/security/bulletins/ms98-017.asp. - Microsoft Knowledge Base (KB) article Q195733, Denial of Service in Applications Using Named Pipes Over RPC http://support.microsoft.com/support/kb/articles/q195/7/33.asp Obtaining Support on this Issue =============================== This is a supported patch. If you have problems installing this patch or require technical assistance with this patch, please contact Microsoft Technical Support. For information on contacting Microsoft Technical Support, please see http://support.microsoft.com/support/contact/default.asp Acknowledgements ================ Microsoft wishes to acknowledge the issue was reported by Mnemonix and the contributions of Internet Security Systems, Inc. (http://www.iss.net) for investigating the problem with us. Revisions ========= - November 20, 1998: Bulletin Created For additional security-related information about Microsoft products, please visit http://www.microsoft.com/security ----------------------------------------------------------------- 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. (c) 1998 Microsoft and/or its suppliers. All rights reserved. For Terms of Use see http://support.microsoft.com/support/misc/cpyright.asp. ******************************************************************* You have received this e-mail bulletin as a result of your registration to the Microsoft Product Security Notification Service. You may unsubscribe from this e-mail notification service at any time by sending an e-mail to MICROSOFT_SECURITY-SIGNOFF-REQUESTat_private The subject line and message body are not used in processing the request, and can be anything you like. For more information on the Microsoft Security Notification Service please visit http://www.microsoft.com/security/bulletin.htm. For security-related information about Microsoft products, please visit the Microsoft Security Advisor web site at http://www.microsoft.com/security.
This archive was generated by hypermail 2b30 : Fri Apr 13 2001 - 14:24:02 PDT