From bugtraq Wed Jun 23 17:24:50 1999 From: aleph1 () UNDERGROUND ! ORG Date: Wed, 23 Jun 1999 17:24:50 +0000 To: bugtraq Subject: Microsoft Security Bulletin (MS99-020) X-MARC-Message: https://marc.info/?l=bugtraq&m=93015856217598 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 (MS99-020) -------------------------------------- Patch Available for "Malformed LSA Request" Vulnerability Originally Posted: June 23, 1999 Summary ======= Microsoft has released a patch that eliminates a vulnerability that poses a denial of service threat to Microsoft(r) Windows NT(r) servers and workstations. A malformed request to the Local Security Authority (LSA) service will causes the service to stop responding, requiring the computer to be restarted. A fully supported patch is available to eliminate the vulnerability, and Microsoft recommends that affected customers download and install it, if appropriate. Issue ===== Windows NT provides the ability to manage user privileges programmatically via the Local Security Authority (LSA) API. The API allows a program to query user names, modify privileges, and change other elements of the security policy, subject to the program's authorizations. Certain API methods do not correctly handle certain types of invalid arguments. The vulnerability is a denial of service threat only, and service can be restored by restarting the machine. There is no capability to use this vulnerability to obtain unauthorized services from LSA. While there are no reports of customers being adversely affected by this vulnerability, Microsoft is proactively releasing this patch to allow customers to take appropriate action to protect themselves against it. Affected Software Versions ========================== - Microsoft Windows NT 4.0 Workstation - Microsoft Windows NT 4.0 Server - Microsoft Windows NT 4.0 Server, Terminal Server Edition, 4.0 What Microsoft is Doing ======================= Microsoft has released patches that fix the problem identified. The patches are available for download from the sites listed below in What Customers Should Do. Microsoft also 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) article on this issue: - Microsoft Knowledge Base (KB) article Q231457, Malformed Request Causes LSA Service to Hang, http://support.microsoft.com/support/kb/articles/q231/4/57.asp (Note: It might take 24 hours from the original posting of this bulletin for the KB article to be visible in the Web-based Knowledge Base.) What Customers Should Do ======================== Microsoft has released patches that fix the problem identified. Microsoft highly recommends that customers evaluate the degree of risk that this vulnerability poses to their systems and determine whether to download and install the patch. The patch can be found at: - ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa /NT40/hotfixes-postSP5/LSA3-fix/ NOTE: The above URL has been word-wrapped for readability More Information ================ Please see the following references for more information related to this issue. - Microsoft Knowledge Base (KB) article Q231457, Malformed Request Causes LSA Service to Hang, http://support.microsoft.com/support/kb/articles/q231/4/57.asp. Obtaining Support on this Issue =============================== If you require technical assistance with this issue, please contact Microsoft Technical Support. For information on contacting Microsoft Technical Support, please see http://support.microsoft.com/support/contact/default.asp. Acknowledgments =============== Microsoft acknowledges BindView Corporation (http://www.bindview.com) for discovering the vulnerability and reporting it to us. Revisions ========= - June 23, 1999: 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) 1999 Microsoft Corporation. All rights reserved. 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