Due to security reasons, Ubuntu advises not to use (Netkit's) ftpd, but to use one of its alternatives instead. I use proftpd:

apt-get install proftpd

Choose standalone installation instead of inetd.

localhost only

Some CMS systems (like Drupal) require FTP access to install modules or plugins automatically, even if you are developing on your local machine. If you need an FTP daemon just for local connections, then create a file /etc/proftpd/conf.d/localhost-only.conf with the following content:

SocketBindTight on

Then restart proftpd. This way external hosts cannot connect to your machine using FTP.