In Artifex Ghostscript before 9.24, attackers able to supply crafted PostScript files to the builtin PDF14 converter could use a use-after-free in copydevice handling to crash the interpreter or possibly have unspecified other impact.
https://www.debian.org/security/2018/dsa-4288
https://www.artifex.com/news/ghostscript-security-resolved/
https://usn.ubuntu.com/3768-1/
https://security.gentoo.org/glsa/201811-12
https://lists.debian.org/debian-lts-announce/2018/09/msg00015.html
https://bugs.ghostscript.com/show_bug.cgi?id=699661
https://access.redhat.com/errata/RHSA-2019:0229
https://access.redhat.com/errata/RHBA-2019:0327
http://git.ghostscript.com/?p=ghostpdl.git%3Ba=commit%3Bh=c432131c3fdb2143e148e8ba88555f7f7a63b25e