sebadorn.de | blog

Mozilla made their Observatory service public, which lets you check the security of sites. A first run resulted in an F for sebadorn.de. Following some of the sug­gestions I could improve that to a B-.

1. Redirect HTTP to HTTPS

Thanks to Let’s Encrypt I already offered HTTPS, but I didn't enforce it. Now visitors to http://sebadorn.de are redirected to https://sebadorn.de. I did so by adding the following rule to my .htaccess file:

<IfModule mod_rewrite.c>
	RewriteEngine On
	RewriteCond %{HTTP_HOST} ^sebadorn\.de [NC]
	RewriteCond %{SERVER_PORT} 80
	RewriteRule ^(.*)$ https://sebadorn.de/$1 [R,L]
</IfModule>

2. Add some more headers

<IfModule mod_headers.c>
	Header always edit Set-Cookie (.*) "$1; HttpOnly; Secure"
	Header set Content-Security-Policy "frame-ancestors 'self'"
	Header set X-Content-Type-Options "nosniff"
	Header set X-Frame-Options "SAMEORIGIN"
	Header set X-XSS-Protection "1; mode=block"
</IfModule>

Set-Cookie

Cookies about to be set received additional directives: HttpOnly and Secure. HttpOnly disallows cookies being read by JavaScript and Secure enforces an HTTPS connection. (Source)

X-Content-Type-Options

Setting this header to nosniff tells browsers not to try and guess the MIME type of contents, which potentially prevents XSS attacks. (Source)

X-Frame-Options

Setting this header to SAMEORIGIN or DENY prevents other pages from displaying the site in a frame which prevents clickjacking. (Source)

X-XSS-Protection

Setting this header to 1; mode=block tells browsers to try and detect XSS attacks and in this case stop loading the page. (Source)