Opera Software Opera Web Browser Transfer Item Pop-up Menu Stack
Overflow Vulnerability

iDefense Security Advisory 05.23.07
http://labs.idefense.com/intelligence/vulnerabilities/
May 23, 2007

I. BACKGROUND

Opera is a cross-platform web browser. More information is available at
http://www.opera.com/

II. DESCRIPTION

Remote exploitation of a stack-based buffer overflow in Opera Software
ASA's Opera Web browser could allow an attacker to execute arbitrary
code on the affected host.

Opera 9.2 supports BitTorrent downloads. If a server sends the browser a
specially crafted BitTorrent header, it can lead to a buffer overflow.
The buffer overflow is triggered when the user right clicks on the item
in the download pane.

III. ANALYSIS

Exploitation of this vulnerability allows an attacker to execute
arbitrary code on the affected host.

The attacker must convince the vulnerable user into clicking a link to a
BitTorrent file.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in the Opera
version 9.2 for Windows. Previous versions may also be affected.

V. WORKAROUND

iDefense is not currently aware of a work around for this issue.

VI. VENDOR RESPONSE

Version 9.21 of Opera has been released to address this issue. More
information can be found at the following URL.

http://www.opera.com/support/search/view/860/

VII. CVE INFORMATION

A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.

VIII. DISCLOSURE TIMELINE

05/08/2007  Initial vendor notification
05/08/2007  Initial vendor response
05/23/2007  Coordinated public disclosure

IX. CREDIT

This vulnerability was reported to iDefense by enhalos.

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X. LEGAL NOTICES

Copyright © 2007 iDefense, Inc.

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Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
 There are no warranties with regard to this information. Neither the
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indirect, or consequential loss or damage arising from use of, or
reliance on, this information.