If you have a web server running on Nginx and have a directory which accepts uploading files either from user OR cms. It is always good to have a bit of protection from the server side to deny executing scripts like PHP in that directory.
Nginx is a web server like Apache. I will not go to which is better and why one should use it. Google is your friend to find that out. Here we will focus on how to install latest stable version of Nginx in CentOS 7. Login to your server.
It happened to me few days back when i try to upload an image via WordPress media library over 1MB of size. WordPress would throw an error HTTP Error.