The TIFFReadRawStrip1 and TIFFReadRawTile1 functions in tif_read.c in libtiff before 4.0.7 allows remote attackers to cause a denial of service (crash) or possibly obtain sensitive information via a negative index in a file-content buffer.
https://security.gentoo.org/glsa/201701-16
http://www.securityfocus.com/bid/91741
http://www.openwall.com/lists/oss-security/2016/07/14/4
http://www.openwall.com/lists/oss-security/2016/07/13/3