I have a Wordpress blog hosted on a server without outgoing network. Therefore, Wordpress cannot check for a new version and/or update automatically to a new version.
Currently, the only ways I'm aware of to update the blog to a new version of WP is to follow the complicated guide here, or to copy it to another host (with outgoing network), update it, and copy it back. Both ways are very complicated.
I'm looking for a way to use the automatic updater of WP without requiring outgoing network on the host. Basically, I'd like to upload
wordpress-4.3.1.zip via FTP, go to the admin panel, and choose "update from zip file:
wordpress-4.3.1.zip". Is there such an option, or a plugin that can help me achieve that?
Edit: Note that I don't have access to run arbitrary code on the server. Basically, I have PHP, MySQL, FTP, and that's it.