Multiple Vendor libexif Integer Overflow Heap Corruption Vulnerability

iDefense Security Advisory 06.13.07
http://labs.idefense.com/intelligence/vulnerabilities/
Jun 13, 2007

I. BACKGROUND

Exchangeable image file format (Exif) is an industry standard image
tagging technology used by many digital camera devices. libexif is an
open source library for handling the Exif format. More information can
be found at the URLs shown below.

http://en.wikipedia.org/wiki/Exif
http://libexif.sourceforge.net/

II. DESCRIPTION

Remote exploitation of a integer overflow vulnerability in libexif, as
included in various vendors' operating system distributions, could
allow attackers to crash the process or execute arbitrary code.

The problem exists while parsing a tagged image with a large number of
Exif components. Applications using this library are susceptible to a
heap overflow when an integer overflow is triggered in the
exif_data_load_data_entry function.

III. ANALYSIS

Exploitation requires that a targeted user process a malicious image
using one of several available tools that utilize libexif for Exif tag
parsing. These tools include, but are not limited to, several
applications included in the GNOME and KDE desktops.

IV. DETECTION

iDefense confirmed the existence of this vulnerability in versions
0.6.13 through 0.6.15 of libexif.

V. WORKAROUND

iDefense is currently unaware of any workarounds for this issue.

VI. VENDOR RESPONSE

The libexif maintainers have released version 0.6.16 of libexif to
address this vulnerability.

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2006-4168 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which standardizes names for
security problems.

VIII. DISCLOSURE TIMELINE

08/16/2006  Initial vendor notification
06/05/2007  Second vendor notification
06/11/2007  Initial vendor response
06/13/2007  Coordinated public disclosure

IX. CREDIT

This vulnerability was discovered by Sean Larsson (iDefense Labs).

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X. LEGAL NOTICES

Copyright © 2007 iDefense, Inc.

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