WordPress already includes for a few versions a API that, by defect, comes active and open to all the users in way reading.
By general norm WordPress and usually is made work on Linux, and in this operating system he can have installed and working many different services.
One of the services that we see very frequently in all the sites with WordPress (and without) is the one of the ups and downs generated by Gravatar. This service allows to associate a transformation (normally a photo that represents a person) with a mail account.
In some occasion certainly you need to mount a WordPress very fast to develop but avoiding to have to mount all the system completely. If this it is your case, you can do it fast and easy.
Without a doubt nginx is one of the best existing Web servers nowadays, but its configuration has to become by means of a configuration file that, by general norm, cannot be modified to the flight.
In the generally most habitual case of WordPress it is than the methods of request GET and POST are only used, being able to extend to HEAD and OPTIONS. The rest of methods generally is not used and they would be possible to be blocked.