The mem_get_bits_rectangle function in base/gdevmem.c in Artifex Software, Inc. Ghostscript 9.20 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted file.
https://security.gentoo.org/glsa/201708-06
https://bugs.ghostscript.com/show_bug.cgi?id=697548