The TIFFFetchNormalTag function in LibTiff 4.0.6 allows remote attackers to cause a denial of service (out-of-bounds read) via crafted TIFF_SETGET_C16ASCII or TIFF_SETGET_C32_ASCII tag values.
https://security.gentoo.org/glsa/201701-16
http://www.securityfocus.com/bid/94419
http://www.openwall.com/lists/oss-security/2016/11/14/7
http://www.openwall.com/lists/oss-security/2016/11/12/2