The fixps script in a2ps 4.14 does not use the -dSAFER option when executing gs, which allows context-dependent attackers to delete arbitrary files or execute arbitrary commands via a crafted PostScript file.
https://security.gentoo.org/glsa/201701-67
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=742902
http://www.securityfocus.com/bid/66660
http://www.debian.org/security/2014/dsa-2892
http://lists.opensuse.org/opensuse-updates/2014-04/msg00021.html