In Artifex Ghostscript 9.23 before 2018-08-24, attackers able to supply crafted PostScript could use uninitialized memory access in the aesdecode operator to crash the interpreter or potentially execute code.
https://access.redhat.com/errata/RHSA-2018:3834
https://lists.debian.org/debian-lts-announce/2018/09/msg00015.html
https://security.gentoo.org/glsa/201811-12
https://support.f5.com/csp/article/K22141757?utm_source=f5support&%3Butm_medium=RSS
https://usn.ubuntu.com/3768-1/