LibTIFF before 4.0.6 mishandles the reading of TIFF files, as demonstrated by a heap-based buffer over-read in the ReadTIFFImage function in coders/tiff.c in GraphicsMagick 1.3.27.
https://sourceforge.net/p/graphicsmagick/bugs/540/
https://gitlab.com/libtiff/libtiff/commit/739dcd28a061738b317c1e9f91029d9cbc157159