#2009-008 Dillo integer overflow

Description:

Dillo, an open source graphical web browser, suffers from an integer overflow
which may lead to a potentially exploitable heap overflow and result in
arbitrary code execution.

The vulnerability is triggered by HTML pages with embedded PNG images, the
Png_datainfo_callback function does not properly validate the width and
height of the image. Specific PNG images with large width and height can be
crafted to trigger the vulnerability.

Affected version:

Dillo <= 2.1

Fixed version:

Dillo >= 2.1.1

Credit: vulnerability report and PoC code received from Tielei Wang
        <wangtielei [at] icst [dot] pku [dot] edu [dot] cn>, ICST-ERCIS.

CVE: CVE-2009-2294

Timeline:

2009-05-21: vulnerability reported received
2009-06-18: contacted dillo maintainer
2009-06-18: maintainer requests PoC
2009-06-19: PoC is supplied
2009-06-19: maintainer provides patch
2009-06-24: revised patch is provided after reporter feedback
2009-06-25: patch is confirmed, maintainer requests one week of time to
            investigate further areas of the browser
2009-07-01: dillo developer proposes security release coordination
2009-07-03: advisory release

Permalink:
http://www.ocert.org/advisories/ocert-2009-008.html

-- 
Andrea Barisani |                Founder & Project Coordinator
          oCERT | Open Source Computer Emergency Response Team

<lcars@ocert.org>                         http://www.ocert.org
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