Multiple Vendor GIMP Multiple Integer Overflow Vulnerabilities

iDefense Security Advisory 07.09.07
http://labs.idefense.com/intelligence/vulnerabilities/
Jul 09, 2007

I. BACKGROUND

The GNU Image Manipulation Program is commonly known as the GIMP. It is
a freely distributed piece of software for such tasks as photo
retouching, image composition and image authoring. It is available, in
many languages, for multiple operating systems. More information is
available at the following URL.

http://www.gimp.org/

II. DESCRIPTION

Remote exploitation of multiple integer overflow vulnerabilities in
several of the image loader plug-ins included with distributions of
'The GIMP' allow attackers to crash The GIMP or potentially execute
arbitrary code with the privileges of the user.

The following lines show the location of some vulnerabilities within the
code responsible for loading the DICOM, PNM, PSD, PSP, Sun RAS, XBM, and
XWD file formats. Each of the files are located within the
plug-ins/common directory of the source code.

  dicom.c:391:      value = g_new0 (guint8, element_length + 4);
  pnm.c:566:  data = g_new (guchar, gimp_tile_height () * info->xres * np);
  pnm.c:628:  data = g_new (guchar, gimp_tile_height () * info->xres *
info->np);
  pnm.c:681:  data = g_new (guchar, gimp_tile_height () * info->xres);
  psd.c:2969:    PSDheader.rowlength = g_malloc (PSDheader.rows *
  psp.c:1225:      pixel = g_malloc0 (height * width * bytespp);
  sunras.c:955:  data = g_malloc (tile_height * width);
  sunras.c:1076:  data = g_malloc (tile_height * width);
  sunras.c:1146:  data = g_malloc (tile_height * width * 3);
  sunras.c:1231:  data = g_malloc (tile_height * width * 3);
  xbm.c:879:  data = (guchar *) g_malloc (width * tileheight);
  xwd.c:1193:  data = g_malloc (tile_height * width);
  xwd.c:1195:  scanline = g_new (guchar, xwdhdr->l_bytes_per_line + 8);
  xwd.c:1352:  data = g_malloc (tile_height * width);
  xwd.c:1441:  data = g_malloc (tile_height * width * 3);
  xwd.c:1601:  data = g_malloc (tile_height * width * 3);
  xwd.c:1812:  data = g_malloc (tile_height * width * bytes_per_pixel);

In each case, an integer value from an untrusted input source has
arithmetic operations performed upon it to calculate the length to
allocate. Since no integer overflow checking is performed, a
potentially exploitable heap overflow may result.

This is not a complete list of integer overflow vulnerabilities in the
code.

III. ANALYSIS

Exploitation allows attackers to execute arbitrary code in the context
of the user opening a malicious image file.

In order to be successful, the attacker must convince the victim into
opening a maliciously crafted image with The GIMP.

IV. DETECTION

iDefense has confirmed that version 2.2.15 of The GIMP is vulnerable on
both Linux and Windows platforms. It is suspected that all previous
versions of the GIMP are also affected.

V. WORKAROUND

Consider moving the affected loader modules from The GIMP's plug-in
directory to another location. The location in the file system may vary
depending on distributions. On Red Hat Linux and Debian systems the
default plug-in directory is /usr/lib/gimp/2.0/plug-ins.

VI. VENDOR RESPONSE

The GIMP maintainers have released version 2.2.16 to address these
vulnerabilities. For more information, consult the following URL.

http://developer.gimp.org/NEWS-2.2

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2006-4519 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

08/17/2006  Initial vendor notification
10/06/2006  Second vendor notification
06/26/2007  Third vendor notification
06/26/2007  Initial vendor response
07/09/2007  Coordinated public disclosure

IX. CREDIT

These vulnerabilities were discovered by Sean Larsson (iDefense Labs).

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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
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