Do nothing further until you have read and understood the contents of that page. Unix permissions are not some mysterious voodoo magic - they are incredibly logical and simple once you understand them.
Take the time required to understand what those "magic" numbers mean, and what they do.
With your newfound clarity and understanding of Unix file/directory permissions and ownership you should now know that
vsftpd does not require any particular permissions, the operating system is just enforcing the restrictions you've given it.
The permissions on a file or directory determine who may perform what actions. You as the system administrator are responsible for setting appropriate permissions on files and directories (which users/groups will need to perform what actions, and what actions "other" users should be permitted to perform).
You determine what permissions are appropriate by the configuration of your server, and which users need to perform which actions in your particular environment.