pdf_set_text_matrix in gdevpdts.c in Artifex Ghostscript through 9.18 allows remote attackers to cause a denial of service (spprint.c pprintg1 stack-based out-of-bounds write) or possibly execute arbitrary code via a crafted PDF document.
Upstream ticket: https://bugs.ghostscript.com/show_bug.cgi?id=699255 Upstream patch: http://git.ghostscript.com/?p=ghostpdl.git;a=commit;h=39b1e54b2968620723bf32e96764c88797714879
Created ghostscript tracking bugs for this issue: Affects: fedora-all [bug 1569821]
oss-security: http://www.openwall.com/lists/oss-security/2018/04/19/5
Statement: Red Hat Enterprise Linux 6 is now in Maintenance Support 2 Phase of the support and maintenance life cycle. This has been rated as having a security impact of Moderate, and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2018:2918 https://access.redhat.com/errata/RHSA-2018:2918
Mitigation: Please refer to the "Mitigation" section of CVE-2018-16509 : https://access.redhat.com/security/cve/cve-2018-16509