the patch come from:
http://cups.org/strfiles/3867/str3867.patch
The LZW decompressor in the LWZReadByte function in giftoppm.c
in the David Koblas GIF decoder in PBMPLUS, as used in the
gif_read_lzw function in filter/image-gif.c in CUPS before 1.4.7,
the LZWReadByte function in plug-ins/common/file-gif-load.c
in GIMP 2.6.11 and earlier, the LZWReadByte function in img/gifread.c
in XPCE in SWI-Prolog 5.10.4 and earlier, and other products,
does not properly handle code words that are absent from the
decompression table when encountered, which allows remote attackers to
trigger an infinite loop or a heap-based buffer overflow, and possibly
execute arbitrary code, via a crafted compressed stream, a related
issue to CVE-2006-1168 and CVE-2011-2895.
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2011-2896
