From secnotif@MICROSOFT.COM Thu Sep 30 21:08:26 1999 From: Microsoft Product Security Resent-From: mea culpa To: MICROSOFT_SECURITY@ANNOUNCE.MICROSOFT.COM Resent-To: jericho@attrition.org Date: Thu, 30 Sep 1999 18:03:53 -0700 Subject: Microsoft Security Bulletin (MS99-041) 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 (MS99-041) -------------------------------------- Tool Available for "RASMAN Security Descriptor" Vulnerability Originally Posted: September 30, 1999 Summary ======= Microsoft has released a patch that eliminates a vulnerability in Microsoft(r) Windows NT(r) 4.0. The vulnerability could enable a user to execute arbitrary code on a Windows NT machine under certain conditions. Frequently asked questions regarding this vulnerability can be found at http://www.microsoft.com/security/bulletins/MS99-041faq.asp. Issue ===== The security descriptor that secures the Remote Access Connection Manager, RASMAN.EXE, contains an inappropriate ACE in its DACL and would allow an unprivileged user to levy requests on it via the Service Control Manager. Among the actions that could be requested is to change the location and name of the executable code for the service. By doing so, a malicious user could substitute arbitrary code for the legitimate service, which then would run in a System Context. A malicious user could only exploit this vulnerability if he or she had a valid userid and password on the target machine. If the machine allowed users to log on from the network, the vulnerability could be remotely exploited. In addition, the arbitrary code could, under certain conditions, reside on a remote machine. A tool is available to reset the permissions to the appropriate value and eliminate the vulnerability, and should be run against any machine that allows unprivileged users to perform either interactive or network logons under any account. Affected Software Versions ========================== - Microsoft Windows NT 4.0 Workstation - Microsoft Windows NT 4.0 Server - Microsoft Windows NT 4.0 Server, Enterprise Edition - Microsoft Windows NT 4.0 Server, Terminal Server Edition Tool Availability ================= - ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/ usa/nt40/Hotfixes-PostSP6/Security/Rasman-fix/ NOTE: Line breaks have been inserted into the above URL for readability. More Information ================ Please see the following references for more information related to this issue. - Microsoft Security Bulletin MS99-041: Frequently Asked Questions, http://www.microsoft.com/security/bulletins/MS99-041faq.asp. - Microsoft Knowledge Base (KB) article Q242294, Security Descriptor Allows Privilege Elevation on Remote Computers, http://support.microsoft.com/support/kb/articles/q242/2/94.asp. (Note: It may take 24 hours from the original posting of this bulletin for this KB article to be visible.) - Microsoft Security Advisor web site, http://www.microsoft.com/security/default.asp. Obtaining Support on this Issue =============================== This is a fully supported patch. Information on contacting Microsoft Technical Support is available at http://support.microsoft.com/support/contact/default.asp. Acknowledgments =============== Microsoft acknowledges Alberto Rodríguez Aragonés for bringing this issue to our attention. Revisions ========= - September 30, 1999: Bulletin Created. --------------------------------------------------------------------- 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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