CVE-2011-3170

La función gif_read_lzw en filter/image-gif.c en CUPS v1.4.8 y anteriores no controla correctamente la primera WORD de código en un flujo LZW, lo que permite provocar un desbordamiento de búfer basado en memoria dinámica (heap) a atacantes remotos, y posiblemente, ejecutar código de su elección, a través de un stream debidamente modificado. Se trata de una vulnerabilidad diferente a la CVE-2011.2896.

The cupsDoAuthentication function in auth.c in the client in CUPS before 1.4.4, when HAVE_GSSAPI is omitted, does not properly handle a demand for authorization, which allows remote CUPS servers to cause a denial of service via HTTP_UNAUTHORIZED responses. 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 and CVE-2011-2895. The gif_read_lzw function in filter/image-gif.c in CUPS 1.4.8 and earlier does not properly handle the first code word in an LZW stream, which allows remote attackers to trigger a heap-based buffer overflow, and possibly execute arbitrary code, via a crafted stream, a different vulnerability than CVE-2011-2896.