/etc/ftpusers is in vsftpd 3.0.2-1ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | # /etc/ftpusers: list of users disallowed FTP access. See ftpusers(5).
root
daemon
bin
sys
sync
games
man
lp
mail
news
uucp
nobody
|