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Multiple Vendor GIMP Multiple Integer Overflow Vulnerabilities

07.09.07

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/

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.

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.

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.

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.

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

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.

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

CREDIT

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

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LEGAL NOTICES

Copyright © 2007 Verisign, 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 author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.