security #6008 Improved nginx config to not expose other php files (peterrehm)

This PR was submitted for the 2.8 branch but it was merged into the 2.3 branch instead (closes #6008).

Discussion
----------

Improved nginx config to not expose other php files

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets | #6005

This should improve the security as all non defined php files will return
a 404 error code instead of providing them as text which is a more sane
solution.

Commits
-------

6545884 Updated according to comments
31a13cb Improved nginx config to not expose other php files

Author: weaverryan

cookbook/configuration/web_server_configuration.rst

@@ -305,6 +305,12 @@ The **minimum configuration** to get your application running under Nginx is:
             # Remove the internal directive to allow URIs like this
             internal;
         }
+        
+        # return 404 for all other php files not matching the front controller
+        # this prevents access to other php files you don't want to be accessible.
+        location ~ \.php$ {
+          return 404;
+        }
 
         error_log /var/log/nginx/project_error.log;
         access_log /var/log/nginx/project_access.log;
@@ -318,14 +324,17 @@ The **minimum configuration** to get your application running under Nginx is:
 .. tip::
 
     This executes **only** ``app.php``, ``app_dev.php`` and ``config.php`` in
-    the web directory. All other files will be served as text. You **must**
-    also make sure that if you *do* deploy ``app_dev.php`` or ``config.php``
-    that these files are secured and not available to any outside user (the
-    IP address checking code at the top of each file does this by default).
+    the web directory. All other files ending in ".php" will be denied.
 
     If you have other PHP files in your web directory that need to be executed,
     be sure to include them in the ``location`` block above.
 
+.. caution::
+
+    After you deploy to production, make sure that you **cannot** access the ``app_dev.php``
+    or ``config.php`` scripts (i.e. ``http://example.com/app_dev.php`` and ``http://example.com/config.php``).
+    If you *can* access these, be sure to remove the ``DEV`` section from the above configuration.
+
 For advanced Nginx configuration options, read the official `Nginx documentation`_.
 
 .. _`Apache documentation`: http://httpd.apache.org/docs/