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Hide Server and Web Application Information

First and foremost, this is security over obscurity. No relevant security improvement is gained by this, but rather just annoy or hopefully prevent automated bots or script kiddies from doing any future damage. By NO means it should be the only defensive mechanism for any site!

This site runs on Drupal. Drupal, by default returns Drupal specific http headers on every request. So I wanted to disabled this completely at the server level, in addition to the PHP and Apache information that is part of a typical stock LAMP configuration.

First, we start with PHP. The PHP X-Powered-By header can be disabled by disabling the expose_php option:

expose_php = Off

Next, is updating the default Server header set by Apache:

ServerTokens Prod

Finally, it's time to remove the X-Generator and X-Drupal-Cache specific Drupal headers.
Using Apache via mod_headers module:

<IfModule mod_headers.c>
     Header unset X-Generator
     Header unset X-Drupal-Cache
</IfModule>

Using Nginx via the headers more module:

more_clear_headers 'x-generator';
more_clear_headers 'x-drupal-cache';

Why stop here when I can set custom headers. So as a joke, I want to tell the world that my sites are powered by Unicors and I’m the hacker being it. Doing so is dead simple.

Nginx

add_header              X-Powered-By "Unicorns";
add_header              X-hacker "Alpha01";

Varnish (vcl_deliver)

set resp.http.X-Powered-By = "Unicorns";
set resp.http.X-hacker = "Alpha01";

Now, let's view my new http headers

alpha03:~ tony$ curl -I https://www.rubysecurity.org
HTTP/1.1 200 OK
Date: Thu, 24 Nov 2016 03:53:40 GMT
Content-Type: text/html; charset=utf-8
Connection: keep-alive
Set-Cookie: __cfduid=d8fbf8e2a27fac74e782224db3fd3c86c1479959620; expires=Fri, 24-Nov-17 03:53:40 GMT; path=/; domain=.rubysecurity.org; HttpOnly
Strict-Transport-Security: max-age=63072000; includeSubdomains; preload
Expires: Sun, 19 Nov 1978 05:00:00 GMT
Cache-Control: public, max-age=300
X-Content-Type-Options: nosniff
Content-Language: en
X-Frame-Options: SAMEORIGIN
Last-Modified: Tue, 22 Nov 2016 06:55:27 GMT
Vary: Cookie,Accept-Encoding
Front-End-Https: on
X-Powered-By: Unicorns
X-hacker: Alpha01
Server: cloudflare-nginx
CF-RAY: 3069ea499a6320ba-LAX

References:
http://php.net/manual/en/ini.core.php#ini.expose-php
http://httpd.apache.org/docs/2.4/mod/core.html#servertokens
https://www.drupal.org/node/982034#comment-4719282
http://nginx.org/en/docs/http/ngx_http_headers_module.html

Programming: 

Awesome Applications: 

Locking Down Drupal Access with Nginx

This site is powered by Drupal. Drupal and WordPress for that matter, are well targeted platforms, mainly because of their large install base on the internet. Quite frankly the reason I bother using both Drupal and WordPress instead of a flat-file based CMS is because I have to deal with these web applications at work on a daily basis, so it's a great way to keep myself current with the technology that's paying my bills.

I have Nginx acting as an SSL proxy for www.rubysecurity.org, which is hosted on an Apache back-end. So I have a few configs that I've enabled to lock down access to my Drupal site. The configs are made at the Nginx proxy level, so they can never reach Apache.

Firstly, I have all of Drupal's /admin locked out from outside access:

        location = /admin {
                allow MY-HOME-IP-ADDRESS;
                deny all;
                return 403;
        }

Next, I only allow login access from my home ip address:

        location = /user {
                allow MY-HOME-IP-ADDRESS;
                deny all;

                proxy_pass https://www.rubysecurity.org/user;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header Host $http_host;
        }

Lastly, since Nginx is unable to process query strings at the location block level, I've setup an additional config to drop all user login query requests.

       if ($args ~* "q=user") {
                set $blockme  M;
        }
        if ($remote_addr != MY-HOME-IP-ADDRESS) {
                set $blockme  "${blockme}E";
        }
        if ($blockme = ME) {
                return 403;
       }

Linux: 

Awesome Applications: 

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