vsftpd stand for "very secure" and the program was built to have strongest protection against possible FTP vulnerabilities.

vstp-very-secure-deamon

# vsftpd - Very Secure Deamon

#  IMPORTANT : add your own data or parameters, I make use of double segments [[ your variable ]]. eg. ssh root@[[ 96.172.44.11 ]] should be replaced with ssh root@888.88.88.88 where "888.88.88.88" is your value, variable etc. I have a habit of using ":::" to indicate line ending and end of paragraph, crazy I know but be warned its just how I write ::: All notes are for my own use & should you use any it's at your own risk, it's NOT a Tutorial :::

# Resource
#   https://help.ubuntu.com/12.04/serverguide/ftp-server.html
#  https://help.ubuntu.com/community/vsftpd
#   http://www.noob2geek.com/linux/setup-vsftpd-debian-ubuntu/


# Install vsftpd
sudo apt-get install vsftpd

# By Default vftpd is installed in the root ( eg./home/ftp )
# for scurity make own directory ( eg. srv )
sudo mkdir -p /srv/ftp
sudo usermod -d /srv/ftp ftp

# Disallow anonymous download /etc/vsftpd.conf by changing
# anonymous_enable=Yes
anonymous_enable=No

# allow the user to write to the directory.
local_enable=YES

# Write permissions
write_enable=YES

# OPTIONAL :

# When this line is set to Yes, all the local users will be jailed within their chroot and will be denied access to any other part of the server.
chroot_local_user=YES
# You can also limit a specific list of users to just their home directories:
chroot_list_enable=NO ( need access to /var/www )

# END OPTIONAL

# set umask to 022 to make sure that all the files (644) and folders (755) you upload get the proper permissions.
local_umask=022

# Save

# Because of a recent vsftpd upgrade, vsftpd is "refusing to run with writable root inside chroot". A handy way to address this issue to is to take the following steps:
# sudo mkdir /home/[[ username ]]/files

# Change the ownership of that file to root
# sudo chown root:root /home/[[ username ]]


# After making the change restart vsftpd:
sudo restart vsftpd


##############################
# IMPORTANT
##############################

# WWW dir in eg. Filezilla
/var/www

# Ensure www permissions are set right
sudo chown -R [[ user ]] /var/www/
sudo chown -R [[ user ]]:www-data /var/www

# File & Dir permissions
sudo find /var/www -type f -exec chmod 664 {} \;  # files
sudo find /var/www -type d -exec chmod 755 {} \;  # directories

# See if your username is part of groups
groups

# Add a user to goups
sudo usermod -a -G group [[ username ]]