CVE-2015-0852 [FreeImage] Integer overflow in PluginPCX.cpp

["pcheng pcheng" <pcheng () gmx com>]

The following bug was reported to upstream and Debian security team. CVE-2015-0852 was assigned by Debian security team.

Name : FreeImage
Affected Version: <= 3.17.0
URL : http://freeimage.sourceforge.net/

Description :
An integer overflow issue in the FreeImage project was reported and fixed recently.
Upstream fix: Revision 1.18 
http://freeimage.cvs.sourceforge.net/viewvc/freeimage/FreeImage/Source/FreeImage/PluginPCX.cpp?view=log&pathrev=MAIN

Details:

The PluginPCX.cpp file(version 3.17.0) has:

371 unsigned width = header.window[2] - header.window[0] + 1;
372 unsigned height = header.window[3] - header.window[1] + 1;
373 unsigned bitcount = header.bpp * header.planes;

However, it's possible that header.window[2] < header.window[0], and also header.window[3] < header.window[1]. In this 
two cases, width and height can be overflowed. And this can lead further issue in the rest of the code. Take the 
following lines for example:

568 for (x = 0; x < width; x++) {
569 bits[x * 3 + FI_RGBA_RED] = pline[x];
570 }

The write operation on buffer bits can help an attacker to corrupt the heap.