It was discovered that the ghostscript type checker did not properly validate certain types. A specially crafted PostScript document could exploit this to crash ghostscript or, possibly, execute arbitrary code in the context of the ghostscript process. Patch: http://git.ghostscript.com/?p=ghostpdl.git;a=commit;h=0edd3d6c
Mitigation: Please see https://bugzilla.redhat.com/show_bug.cgi?id=1619748#c3
Upstream Patch: http://git.ghostscript.com/?p=ghostpdl.git;a=commit;h=0edd3d6c
Upstream bug report (still not public): https://bugs.ghostscript.com/show_bug.cgi?id=699659 Correct upstream fix is noted in comment 5 rather than comment 0.
This has been public for a while, via both upstream commit and the following upstream annoncement: https://www.artifex.com/news/ghostscript-security-resolved/
Created ghostscript tracking bugs for this issue: Affects: fedora-all [bug 1628536]
Statement: This issue affects the versions of ghostscript as shipped with Red Hat Enterprise Linux 5, 6, and 7. 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 Important, 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/. Red Hat Enterprise Linux 5 is now in Extended Life Phase of the support and maintenance life cycle. This issue 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-2018:3650 https://access.redhat.com/errata/RHSA-2018:3650