A flaw was found in the setsystemparams procedure where it did not properly secure its privileged calls, enabling scripts to bypass -dSAFER
restrictions. A specially crafted PostScript file could disable security protection and then have access to the file system, or execute arbitrary commands.
Please refer to the "Mitigation" section of CVE-2018-16509 : <https://access.redhat.com/security/cve/cve-2018-16509>