tools/tiffcrop.c in LibTIFF 4.0.7 allows remote attackers to cause a denial of service (heap-based buffer over-read and buffer overflow) or possibly have unspecified other impact via a crafted TIFF image, related to "READ of size 1" and libtiff/tif_fax3.c:413:13.
https://github.com/vadz/libtiff/commit/9657bbe3cdce4aaa90e07d50c1c70ae52da0ba6a
https://blogs.gentoo.org/ago/2017/01/01/libtiff-multiple-heap-based-buffer-overflow/