Code:  _TIFFmalloc(tmsize_t s)
 {
 	return (malloc((size_t) s));
 }

Vulnerability Type: DoS 
CWE ID: CWE-369
Summary: The _TIFFmalloc function in tif_unix.c in LibTIFF 4.0.3 does not reject a zero size, which allows remote attackers to cause a denial of service (divide-by-zero error and application crash) via a crafted TIFF image that is mishandled by the TIFFWriteScanline function in tif_write.c, as demonstrated by tiffdither.
Commit Message: * libtiff/tif_{unix,vms,win32}.c (_TIFFmalloc): ANSI C does not
require malloc() to return NULL pointer if requested allocation
size is zero.  Assure that _TIFFmalloc does.