libtiff: out-of-bounds write in the tiff2rgba tool

Multiple integer overflows in the 1 cvtbystrip and 2 cvtbytile functions in the tiff2rgba tool in LibTIFF 4.0.6 and earlier, when -b mode is enabled, allow remote attackers to cause a denial of service crash or execute arbitrary code via a crafted TIFF image, which triggers an out-of-bounds write...