/usr/share/courier/ is in courier-webadmin 0.76.3-5+deb9u1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/courier/webadmin/
/usr/share/courier/webadmin/admin-00machine.html
/usr/share/courier/webadmin/admin-00machine.pl
/usr/share/courier/webadmin/admin-10password.html
/usr/share/courier/webadmin/admin-10password.pl
/usr/share/courier/webadmin/admin-15mysql.html
/usr/share/courier/webadmin/admin-15mysql.pl
/usr/share/courier/webadmin/admin-15pgsql.html
/usr/share/courier/webadmin/admin-15pgsql.pl
/usr/share/courier/webadmin/admin-20aliases.html
/usr/share/courier/webadmin/admin-20aliases.pl
/usr/share/courier/webadmin/admin-cancel.pl
/usr/share/courier/webadmin/admin-main.html
/usr/share/courier/webadmin/admin-main.pl
/usr/share/courier/webadmin/admin-save.html
/usr/share/courier/webadmin/admin-save.pl
/usr/share/courier/webadmin/dumpenv.pl
/usr/share/courier/webadmin/login.html
/usr/share/courier/webadmin/notsupp.html
/usr/share/courier/webadmin/unsecure.html
/usr/share/courier/webadmin/webadmin.pl
/usr/share/courier/webadmin/webadmin.pm