In AWStats through 7.8, cgi-bin/awstats.pl?config= accepts a partial absolute pathname (omitting the initial /etc), even though it was intended to only read a file in the /etc/awstats/awstats.conf format. NOTE: this issue exists because of an incomplete fix for CVE-2017-1000501 and CVE-2020-29600.
https://lists.debian.org/debian-lts-announce/2020/12/msg00035.html