Libtiff 4.0.6 tiffcrop _TIFFFax3fillruns: divide by zero
Posted on 30 November -0001
<HTML><HEAD><TITLE>libtiff 4.0.6 tiffcrop _TIFFFax3fillruns(): divide by zero</TITLE><META http-equiv="Content-Type" content="text/html; charset=utf-8"></HEAD><BODY>Details ======= Product: libtiff Affected Versions: <= 4.0.6 Vulnerability Type: divide by zero Vendor URL: http://www.remotesensing.org/libtiff/ Credit: Kaixiang Zhang of the Cloud Security Team, Qihoo 360 CVE ID: CVE-2016-5323 Tested system version: fedora23 32bit fedora23 64bit CentOS Linux release 7.1.1503 64bit Introduction ======= t was always corrupted when I use tiffcrop command followed by a crafted TIFF image in function _TIFFFax3fillruns () without checking the value of divisor, it causes a divide by zero flaw. Attackers cound exploit this issue to cause denial-of-service. Here is the stack info: gdb –args ./tiffcrop _TIFFFax3fillruns.tif tmpout.tif --- --- Program received signal SIGSEGV, Segmentation fault. 0x00007ffff7ad97f0 in _TIFFFax3fillruns (buf=0x0, runs=0x673500, erun=<optimized out>, lastx=64) at tif_fax3.c:407 407 ZERO(n, cp); (gdb) bt #0 0x00007ffff7ad97f0 in _TIFFFax3fillruns (buf=0x0, runs=0x673500, erun=<optimized out>, lastx=64) at tif_fax3.c:407 #1 0x00007ffff7ae087c in Fax3DecodeRLE (tif=0x662010, buf=0x0, occ=8192, s=<optimized out>) at tif_fax3.c:1527 #2 0x00007ffff7ba3739 in TIFFReadEncodedTile (tif=tif@entry=0x662010, tile=8, buf=0x0, size=8192, size@entry=-1) at tif_read.c:668 #3 0x00007ffff7ba3a01 in TIFFReadTile (tif=tif@entry=0x662010, buf=<optimized out>, x=x@entry=0, y=y@entry=0, z=z@entry=0, s=s@entry=8) at tif_read.c:641 #4 0x0000000000443e41 in readSeparateTilesIntoBuffer (bps=1, spp=129, tl=1024, tw=64, imagewidth=32, imagelength=32, obuf=0x7ffff7ee5010 "", in=0x662010) at tiffcrop.c:994 #5 loadImage (in=in@entry=0x662010, image=image@entry=0x7fffffff7960, dump=dump@entry=0x7fffffffc270, read_ptr=read_ptr@entry=0x7fffffff7920) at tiffcrop.c:6079 #6 0x0000000000403209 in main (argc=<optimized out>, argv=<optimized out>) at tiffcrop.c:2278 (gdb) p cp $2 = (unsigned char *) 0x0</BODY></HTML>
