Hash: SHA1

             AUSCERT External Security Bulletin Redistribution

                    ESB-2007.0628 -- [Win][UNIX/Linux]
               Yahoo! Messenger webcam stream heap overflow
                              20 August 2007


        AusCERT Security Bulletin Summary

Product:              Yahoo! Messenger
Publisher:            US-CERT
Operating System:     Windows
                      UNIX variants (UNIX, Linux, OSX)
Impact:               Execute Arbitrary Code/Commands
Access:               Remote/Unauthenticated

Original Bulletin:    http://www.kb.cert.org/vuls/id/515968

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Vulnerability Note VU#515968

Yahoo! Messenger webcam stream heap overflow


Yahoo! Messenger fails to properly handle webcam streams, which may allow a
remote attacker to execute arbitrary code.

I. Description

Yahoo! Messenger is an instant messaging application that is available for
Windows, Mac, Unix, web, and mobile systems. Some version of Yahoo! Messenger,
such as the Windows and Mac versions, support webcam use. When Yahoo!
Messenger views a webcam stream, it makes a connection to port 5100/tcp. The
webcam video stream is sent as a JPEG 2000 code stream. Yahoo! Messenger
appears to require user interaction to connect a webcam stream.

Yahoo! Messenger contains a heap overflow in the handling of a malformed JPEG
2000 code streams. Exploit code that causes a denial of service is publicly

II. Impact

A remote attacker may be able to execute arbitrary code with the privileges
of the user running Yahoo! Messenger. This vulnerability may also cause a
denial of service by causing Yahoo! Messenger to crash.

III. Solution

Restrict network access
This vulnerability can be mitigated by blocking outgoing connections to
5100/tcp. This appears to prevent Yahoo! Messenger from connecting to a
webcam stream.

Do not accept webcam invitations
Until this vulnerability has been addressed by the vendor, do not accept any
Yahoo! Messenger webcam invitations, regardless of the source.

Systems Affected

Vendor          Status          Date Updated
Yahoo, Inc.     Vulnerable      17-Aug-2007




This vulnerability was publicly disclosed by team509.

This document was written by Will Dormann.

Other Information

Date Public             15/08/2007
Date First Published    17/08/2007 11:15:44
Date Last Updated       17/08/2007
CERT Advisory
CVE Name
Metric                  7.70
Document Revision       5

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