From secnotif@MICROSOFT.COM Thu Sep 6 18:49:19 2001 From: Microsoft Product Security To: MICROSOFT_SECURITY@ANNOUNCE.MICROSOFT.COM Date: Thu, 6 Sep 2001 16:26:07 -0700 Subject: Microsoft Security Bulletin MS01-047 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: OWA Function Allows Unauthenticated User to Enumerate Global Address List Date: 06 September 2001 Software: Exchange 5.5 Impact: Information Disclosure Bulletin: MS01-047 Microsoft encourages customers to review the Security Bulletin at: http://www.microsoft.com/technet/security/bulletin/MS01-047.asp. - ---------------------------------------------------------------------- Issue: ====== Among the functions Outlook Web Access (OWA) in Exchange 5.5 offers is the ability to search the global address list (GAL). By design, this is an authenticated function, implemented as a two-tier architecture - a front tier that provides a user interface and a back-end tier that actually performs the search. However, only the front tier actually checks authentication. An attacker who sent a properly formatted request to the back-end function that actually performs the search could enumerate the GAL without authenticating. Mitigating Factors: ==================== - The vulnerability would only allow the attacker to learn users' email aliases. It would not provide any other capabilities. Specifically, it would not give the attacker any way to create or send mail as a user; to read, change or delete mail; or to perform any other functions on the server. - The vulnerability is only exploitable via OWA. Exchange servers that are not configured to offer OWA are not affected by the vulnerability. - The vulnerability does not affect Exchange 2000, even when offering OWA. Patch Availability: =================== - A patch is available to fix this vulnerability. Please read the Security Bulletin at http://www.microsoft.com/technet/security/bulletin/ms01-047.asp for information on obtaining this patch. Acknowledgment: =============== - Noam Rathaus from SecuriTeam.com (http://www.SecuriTeam.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 iQEVAwUBO5gGDo0ZSRQxA/UrAQHaXwf/bp/hBPgvX6An29J9LDUlNSyIU2m29Ud0 E2D09DAQL35DsgOnikesAzmo5u/6IsyBqtMxRBzQLgBuvBo52JlJI4gbsqZBzqLW G+jtw7G+xdPZh3nkFRT9QPBRmdrP2JLz9fuW5Hb3BoEG39BVWUIlHfhcQHXrNv3W S1FRYe9hpG4okRaEn5C2hAxc4eQSLw3AvB9+2b2AXVrvj2naSLkXmE0ZssO84qBN d9fIq79sDTLz0lifu2NBHxiU+mhMjil+h3bqrkcETBPKdjBqvWHa+0LIDZhz0xPm IdDaaWwkXkimX9Gwi9wmRozm6AgxBpHJM/vpBKssCvskuKa9zvccJA== =wUFJ -----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.