- install vsftpd-pkg

- customize /etc/vsftpd.conf (see man vsftpd.conf.5)
write_enable=yes
anonymous_enable=yes
anon_upload_enable=yes
anon_mkdir_write_enable=yes  (needs write-permissions on the parent-dir by anonymous, /home/ftp must not be writable, create subdir e.g. /"home/ftp/upload")
# ??? nopriv_user=

- done