The read_buf function in stream.c in rzip 2.1 allows remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted archive.
https://lists.debian.org/debian-lts-announce/2020/04/msg00022.html
https://blogs.gentoo.org/ago/2017/04/29/rzip-heap-based-buffer-overflow-in-read_buf-stream-c/