Home page logo
/

bugtraq logo Bugtraq mailing list archives

CERT Advisory CA-2002-16 Multiple Vulnerabilities in Yahoo! Messenger
From: CERT Advisory <cert-advisory () cert org>
Date: Wed, 5 Jun 2002 15:05:22 -0400 (EDT)



-----BEGIN PGP SIGNED MESSAGE-----

CERT Advisory CA-2002-16 Multiple Vulnerabilities in Yahoo! Messenger

   Original release date: June 05, 2002
   Last revised: --
   Source: CERT/CC

   A complete revision history can be found at the end of this file.

Systems Affected

     * Yahoo!  Messenger  version  5,0,0,1064  and  prior  for  Microsoft
       Windows

Overview

   There are multiple vulnerabilities in Yahoo! Messenger. Attackers that
   are  able  to  exploit  these  vulnerabilities  may be able to execute
   arbitrary  code  with  the  privileges of the victim user. We have not
   seen  active  scanning for these vulnerabilities, nor have we received
   any reports of these vulnerabilities being exploited, but users should
   upgrade to version 5,0,0,1065 or later.

I. Description

   Yahoo! Messenger is a widely used program for communicating with other
   users  over the Internet. On May 27, 2002, a buffer overflow and a URL
   validation  vulnerability  were  discovered  in  the  Yahoo! Messenger
   client for Microsoft Windows. Details of each vulnerability follow:

     VU#137115  - Yahoo! Messenger contains a buffer overflow in the URI
     handler

     The  buffer  overflow  occurs  during  the processing of the Yahoo!
     Messenger  URI  handler  (ymsgr:). This URI handler is installed at
     the system level for applications that use the underlying operating
     system when processesing URIs (such as Microsoft Internet Explorer,
     Netscape  Navigator  6, Microsoft Outlook, or the command shell). A
     URI  can  be  sent  by  another Yahoo! Messenger user in a message,
     embedded  in  a  web  site,  or  sent  in  an HTML-renderable email
     message.

     This vulnerability has been assigned as CAN-2002-0031 by the Common
     Vulnerabilities and Exposures (CVE) group:

     http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-0031

     VU#172315  -  Yahoo!  Messenger  "addview"  function allows for the
     automatic execution of malicious script contained in web pages

     A  vulnerability  exists in the Yahoo! Messenger "addview" function
     that permits a remote attacker to execute arbitrary script and HTML
     in  the  Internet security zone of the local machine. The "addview"
     function  is  only  supposed to accept view information from Yahoo!
     servers. However, an attacker can send malicious script and HTML to
     the client using the Yahoo! URL redirection service. This script or
     HTML is interpreted by the Yahoo! Messenger client and is displayed
     in the client's web browser.

     This vulnerability has been assigned as CAN-2002-0032 by the Common
     Vulnerabilities and Exposures (CVE) group:

     http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-0032

   These  vulnerabilities  were  resolved  in  Yahoo!  Messenger  version
   5,0,0,1065,  released May 22, 2002; however, a bug in the distribution
   server  may  have  inadvertantly  installed  Yahoo!  Messenger version
   5,0,0,1036  on  systems that downloaded Yahoo! Messenger after May 22,
   2002. The bug in the distribution server has since been resolved.

   In  February  2002,  the  following  vulnerabilities  were reported to
   affect Yahoo! Messenger:

     * http://www.kb.cert.org/vuls/id/393195
     * http://www.kb.cert.org/vuls/id/419419
     * http://www.kb.cert.org/vuls/id/755755
     * http://www.kb.cert.org/vuls/id/887319
     * http://www.kb.cert.org/vuls/id/952875

   All of these vulnerabilities were resolved in Yahoo! Messenger version
   5,0,0,1058,  released February 25, 2002, or by server-side resolutions
   around the same time.

II. Impact

   A  remote  attacker  can execute arbitrary code with the privileges of
   the  victim  user,  cause  a  denial of service, or modify data in the
   victim's buddy list.

III. Solution

   Upgrade to the latest version of Yahoo! Messenger

     On  May  22,  2002,  Yahoo!  released  a  fixed  version  of Yahoo!
     Messenger  (5,0,0,1065)  and began issuing a patch (5,0,0,1066) via
     the  AutoUpdater to address this issue. All users should upgrade to
     version   5,0,0,1065   or  later.  Users  with  versions  prior  to
     5,0,0,1066  that  have "Auto Update" enabled will receive a message
     informing  them  that  an  upgrade  is  available. All users should
     accept this upgrade.

     Users who downloaded Yahoo! Messenger after May 22, 2002, should be
     aware  that a bug in the distribution server may have inadvertantly
     installed  Yahoo! Messenger version 5,0,0,1036, which is vulnerable
     to  all issues in this advisory. The bug in the distribution server
     has since been resolved.

     Users  should upgrade and verify the version of Yahoo! Messenger by
     selecting  the  "About  Yahoo!  Messenger..."  option from the Help
     menu.

   Implement a firewall and filtering

     Yahoo! Messenger listens for peer-to-peer requests on port 5101/TCP
     but  users  can  implement a firewall to block inbound and outbound
     access  to port 5101/TCP. However, since Yahoo! Messenger URI's can
     be  embedded  in  a web site or email message, blocking requests to
     and from port 5101/TCP is not a completely effective solution. Mail
     and  Internet filters should also be applied to filter the "ymsgr:"
     URI handler from email messages and web sites.

Appendix A. - Vendor Information

   This  appendix  contains  information  provided  by  vendors  for this
   advisory.  When  vendors  report  new  information  to the CERT/CC, we
   update this section and note the changes in our revision history. If a
   particular  vendor  is  not  listed  below, we have not received their
   comments.

Yahoo!, Inc.

     Yahoo!  encourages  users to upgrade to the latest version whenever
     prompted by the AutoUpdater or regularly check for updated versions
     of the client at http://messenger.yahoo.com.
     _________________________________________________________________

   The     CERT     Coordination    Center    thanks    Scott    Woodward
   <scott () phoenixtechie com>, Phuong Nguyen <dphuong () yahoo com>, and Adam
   Lang <themeetup () hotmail com> for their discovery and analysis of these
   vulnerabilities.   We  also  thank  Yahoo!  for  their  assistance  in
   analyzing and responding to these issues.
     _________________________________________________________________

   Feedback can be directed to the author: Jason A. Rafail
     _________________________________________________________________

Appendix B. - References

    1. http://www.kb.cert.org/vuls/id/137115
    2. http://www.kb.cert.org/vuls/id/172315
    3. http://www.kb.cert.org/vuls/id/393195
    4. http://www.kb.cert.org/vuls/id/419419
    5. http://www.kb.cert.org/vuls/id/755755
    6. http://www.kb.cert.org/vuls/id/887319
    7. http://www.kb.cert.org/vuls/id/952875
   ______________________________________________________________________

   This document is available from:
   http://www.cert.org/advisories/CA-2002-16.html
   ______________________________________________________________________

CERT/CC Contact Information

   Email: cert () cert org
          Phone: +1 412-268-7090 (24-hour hotline)
          Fax: +1 412-268-6989
          Postal address:
          CERT Coordination Center
          Software Engineering Institute
          Carnegie Mellon University
          Pittsburgh PA 15213-3890
          U.S.A.

   CERT/CC   personnel   answer  the  hotline  08:00-17:00  EST(GMT-5)  /
   EDT(GMT-4)  Monday  through  Friday;  they are on call for emergencies
   during other hours, on U.S. holidays, and on weekends.

Using encryption

   We  strongly  urge you to encrypt sensitive information sent by email.
   Our public PGP key is available from
   http://www.cert.org/CERT_PGP.key

   If  you  prefer  to  use  DES,  please  call the CERT hotline for more
   information.

Getting security information

   CERT  publications  and  other security information are available from
   our web site
   http://www.cert.org/

   To  subscribe  to  the CERT mailing list for advisories and bulletins,
   send  email  to majordomo () cert org  Please include in the body of your
   message

   subscribe cert-advisory

   *  "CERT"  and  "CERT  Coordination Center" are registered in the U.S.
   Patent and Trademark Office.
   ______________________________________________________________________

   NO WARRANTY
   Any  material furnished by Carnegie Mellon University and the Software
   Engineering  Institute  is  furnished  on  an  "as is" basis. Carnegie
   Mellon University makes no warranties of any kind, either expressed or
   implied  as  to  any matter including, but not limited to, warranty of
   fitness  for  a  particular purpose or merchantability, exclusivity or
   results  obtained from use of the material. Carnegie Mellon University
   does  not  make  any warranty of any kind with respect to freedom from
   patent, trademark, or copyright infringement.
     _________________________________________________________________

   Conditions for use, disclaimers, and sponsorship information

   Copyright 2002 Carnegie Mellon University.

   Revision History
      June 05, 2002:  Initial release

-----BEGIN PGP SIGNATURE-----
Version: PGP 6.5.8

iQCVAwUBPP5cYaCVPMXQI2HJAQGAUAQAh/Xuz419nzyhbV8Oif1WDa2qczCF8ETW
hYzkQYsi7tXg+kR4GcHfWgFDwlB4F4ojVoe7uBdKfasmQ7lfWXx2V+xxSm7LIbou
6YItFjt8CXPnC6WS+4ODjfr8U+hFRw2AIoUTcewwFT1PMHEMjtunQaiEJkXLqGkM
YAhQ31TZF6Y=
=jGbu
-----END PGP SIGNATURE-----


  By Date           By Thread  

Current thread:
  • CERT Advisory CA-2002-16 Multiple Vulnerabilities in Yahoo! Messenger CERT Advisory (Jun 05)
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]
AlienVault