When you first install Linux, it comes with a lot of Internet services running, including mail, telnet, finger
and FTP. You really should disable all those that you don't need from /etc/inetd.conf and your startup scripts.
FTP may be very useful, but must be configured correctly. It can allow people to log into their accounts, it
can allow anonymous users to login to a public software directory, and it can display nice messages to them.
The files that you will probably want to modify are /etc/ftpusers and /etc/ftpaccess.The file /etc/ftpusers is very simple. It lists the people that will not be allowed to use FTP to your system. Theroot account, and other system accounts should be in that file.
The file /etc/ftpaccess is a bit more complex and controls the behaviour of the FTP server. It tells it what to
use as README file to display on a directory listing, what kind of logs to create and what messages to
Note that if you create an anonymous FTP area, you will need to read the FTP man page and do exactly what
it tells you to avoid possible security risks.
"Windows Linux Tips: FTP access restrictions"
Reference : techpraveen.com