Use-after-free vulnerability in Ghostscript 9.20 might allow remote attackers to execute arbitrary code via vectors related to a reference leak in .setdevice.
https://security.gentoo.org/glsa/201702-31
https://bugs.ghostscript.com/show_bug.cgi?id=697179
http://www.securityfocus.com/bid/95336
http://www.openwall.com/lists/oss-security/2016/10/05/15