What all Developers need to know about: Security Headers

Posted by Martijn van Lambalgen on August 1, 2018

— This post is part of a series of monthly blog posts about all kinds of Security topics for Developers —

Adding security headers is usually a quick win when improving the security of your web application, but nowadays there’s so many to choose from. Or shouldn’t you choose at all? Why not add all of them? How does this work? We tried to make an overview of which headers improve your security, and what they actually try to achieve for you.

Let’s start at the beginning. The HTTP protocol tells you to specify the HTTP protocol version, add a bunch of headers and optionally include a body for your request/response. The response headers can be thought of as meta data to the response, or as additional instructions for the browser. E.g. it tells the browser which content type the reponse page has, what server handled the request, or how long the requested resource can be cached. Below is an example of an HTTP response. The relevant security headers are marked in red.

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What all Developers need to know about: Clickjacking

Posted by Martijn van Lambalgen on January 17, 2018

— This post is part of a series of blog post about all kinds of Security topics for Developers —

Clickjacking is still one of those amazingly simple attacks that are also easy to prevent. That is, if you know what clickjacking is, because considering the amount of websites that are vulnerable, not many developers know about this.

In a clickjacking attack, an attacker attempts to ‘hijack’ clicks by making the user think he is clicking something else. The basic idea here is that the attacker loads the thing he wants you to click on in an invisible iframe and then shows you something else. For example, you may see a button ‘Click here to get a Free iPad’, but when trying to click it the button, the click-event goes to a ‘Transfer $1000,- from my creditcard’ button in the invisible iframe. Clickjacking may cause all kinds of harm to the user. E.g. the hacker may get access to your webcam, steal money, send emails on your behalf, or worse… It is possible to hijack basically any type of event in the browser (like mouse events or key strokes) if the website that executes that action is not properly secured.

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