From secnotif@MICROSOFT.COM Tue Sep 11 15:58:48 2001 From: Microsoft Product Security To: MICROSOFT_SECURITY@ANNOUNCE.MICROSOFT.COM Date: Mon, 10 Sep 2001 12:53:14 -0700 Subject: Microsoft Security Bulletin MS01-048 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. ******************************** -----BEGIN PGP SIGNED MESSAGE----- - ---------------------------------------------------------------------- Title: Malformed Request to RPC Endpoint Mapper can Cause RPC Service to Fail Date: 10 September 2001 Software: Microsoft(r) Windows NT(r) 4.0 Impact: Denial of service Bulletin: MS01-048 Microsoft encourages customers to review the Security Bulletin at: http://www.microsoft.com/technet/security/bulletin/MS01-048.asp. - ---------------------------------------------------------------------- Issue: ====== The RPC endpoint mapper allows RPC clients to determine the port number currently assigned to a particular RPC service. The Windows NT 4.0 endpoint mapper contains a flaw that causes it to fail upon receipt of a request that contains a particular type of malformed data. Because the endpoint mapper runs within the RPC service itself, exploiting this vulnerability would cause the RPC service itself to fail, with the attendant loss of any RPC-based services the server offers, as well as potential loss of some COM functions. Normal service could be restored by rebooting the server. Mitigating Factors: ==================== - Standard security recommendations call for port 135 - the port on which the RPC endmapper operates - to be blocked at the firewall. If this were done, Internet-based attackers would not be able to exploit this vulnerability. Patch Availability: =================== - A patch is available to fix this vulnerability. Please read the Security Bulletin at http://www.microsoft.com/technet/security/bulletin/ms01-048.asp for information on obtaining this patch. Acknowledgment: =============== - Seiichi Tatsukawa of Rational Software (http://www.rational.com) - --------------------------------------------------------------------- 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. -----BEGIN PGP SIGNATURE----- Version: PGP 7.1 iQEVAwUBO50aKY0ZSRQxA/UrAQFPHgf/YxYPF2gO8Tdqc9GvRoBJacS40wNenPye avi2L8bsuBnZJEJvhzClyRzeJJqCAjMTgNyiMYz/2Ws9wvI4Ooe7tPvBdKb7KTDI zRkPcJx0QRXjigxgspgIgo7V1VViH3TIPEwo54p9905uO255oz0siIjOgmmuVgHH SrPFPyn8rmD7Ic1X343TiyQAx2mLPwaWGmfBJHc+/rgoZIEsgRRL6jX7tLl0NI6C aQUjKvtHeLl5r246G0dHd+p5J36/ebQscZvM8cw+UjZb3+SGkI+1cvr0bzRwSrYv Qr9mi8KUvpTyI8dMooTnfDC1tsde726j7noR5Fk+JasLP4CDeq1Wvw== =J5Cf -----END PGP SIGNATURE----- ******************************************************************* 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-REQUEST@ANNOUNCE.MICROSOFT.COM The subject line and message body are not used in processing the request, and can be anything you like. To verify the digital signature on this bulletin, please download our PGP key at http://www.microsoft.com/technet/security/notify.asp. For more information on the Microsoft Security Notification Service please visit http://www.microsoft.com/technet/security/notify.asp. For security-related information about Microsoft products, please visit the Microsoft Security Advisor web site at http://www.microsoft.com/security.