/usr/share/doc/nut-cgi/changelog.Debian.gz is in nut-cgi 2.7.1-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/nut-cgi/../libupsclient3/changelog.Debian.gz
/usr/share/doc/nut-cgi/../libupsclient3/changelog.Debian.gz