StampyCode

This plugin addresses the need for a simple way to add HTTP headers to outbound HTTP responses in your site.
These headers can include custom ones specific to your application, or can be security related. Some you may wish to specify to protect your site may include:
<ul>
<li>Public-Key-Pins</li>
<li>Strict-Transport-Security</li>
<li>X-Frame-Options</li>
<li>X-XSS-Protection</li>
<li>X-Content-Type-Options</li>
<li>Content-Security-Policy</li>
<li>Content-Security-Policy-Report-Only</li>
</ul>
<h3>Related Links</h3>
<ul>
<li><a href="http://www.troyhunt.com/2015/09/introducing-you-to-browser-security.html" rel="nofollow ugc">Troy Hunt – Introducing you to browser security headers on Pluralsight</a></li>
<li><a href="https://app.pluralsight.com/library/courses/browser-security-headers" rel="nofollow ugc">PluralSight.com – Introduction to Browser Security Headers</a></li>
<li><a href="https://www.owasp.org/index.php/List_of_useful_HTTP_headers" rel="nofollow ugc">OWASP – List of useful HTTP headers</a></li>
<li><a href="https://scotthelme.co.uk/hardening-your-http-response-headers/" rel="nofollow ugc">Scott Helme – Hardening your HTTP response headers</a></li>
</ul>

Headit

Headit is a simple plugin to allow you to add custom HTTP response headers to your site.

Julio Potier

The <a href="http://en.wikipedia.org/wiki/Cross-site_request_forgery" rel="nofollow ugc">CSRF</a> vulnerability is the most famous web vulnerability, since … i do not remember, too long !
Many WordPress plugin (about 70%) from this repository or elsewhere, even Premim plugins are vunerable to this flaw.
To avoid get hacked because os this, just install this plugin, no settings, no tech. Just use your blog as usual.
! ONLY FOR BACK-END USAGE !

Anti CSRF

The CSRF vulnerability is the most famous web vulnerability, since ... i do not remember, too long !

Headit vs Anti CSRF