https://security-tracker.debian.org/tracker/DSA-6024-1
ghostscript before version 0.14 is vulnerable to a heap based buffer overflow that was found in the ghostscript jbig2_decode_gray_scale_image function which is used to decode halftone segments in a JBIG2 image. A document (PostScript or PDF) with an embedded, specially crafted, jbig2 image could trigger a segmentation fault in ghostscript.
In Artifex Ghostscript through 9.25, the setpattern operator 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. This is a type confusion issue because of failure to check whether the Implementation of a pattern dictionary was a structure type.
A flaw was found in ghostscript. The fix for CVE-2020-16305 in ghostscript was not included in RHSA-2021:1852-06 advisory as it was claimed to be. This issue only affects the ghostscript package as shipped with Red Hat Enterprise Linux 8.