The _TIFFmalloc function in tif_unix.c in LibTIFF 4.0.3 does not reject a zero size, which allows remote attackers to cause a denial of service (divide-by-zero error and application crash) via a crafted TIFF image that is mishandled by the TIFFWriteScanline function in tif_write.c, as demonstrated by tiffdither.
http://lists.apple.com/archives/security-announce/2015/Jun/msg00001.html
http://lists.apple.com/archives/security-announce/2015/Jun/msg00002.html
http://openwall.com/lists/oss-security/2015/01/24/15
http://rhn.redhat.com/errata/RHSA-2016-1546.html
http://rhn.redhat.com/errata/RHSA-2016-1547.html
https://bugzilla.redhat.com/show_bug.cgi?id=1185817
https://github.com/vadz/libtiff/commit/3c5eb8b1be544e41d2c336191bc4936300ad7543
https://security.gentoo.org/glsa/201701-16
http://support.apple.com/kb/HT204941