Code Review Doctor
Posted on December 11, 2020
Clickjacking is an attack where one of your logged-in user visits a malicious website, and that website tricks the user into interacting with your website via an iframe.
Ready for a Django security challenge? Play our Django security challenge.
As an example, see the green "create pull request" button on https://django.doctor - which will create a Pull Request on GitHub as the logged in user:
Let's say the malicious website has some nefarious React:
import React from 'react';
export default function (props) {
const [position, setPosition] = React.useState({ clientX: 0, clientY: 0 });
const updatePosition = event => {
const { pageX, pageY, clientX, clientY } = event;
setPosition({ clientX, clientY,});
};
React.useEffect(() => {
document.addEventListener("mousemove", updatePosition, false);
document.addEventListener("mouseenter", updatePosition, false);
return () => {
document.removeEventListener("mousemove", updatePosition);
document.removeEventListener("mouseenter", updatePosition);
};
}, []);
return (
<>
<iframe
style={{zIndex: 100, position: 'absolute', top: position.clientY-200, left: position.clientX-650}}
src="<path-to-target-website>"
width="750px"
height="500px"
/>
<div>Some website content</div>
</>
);
}
When one of https://django.doctor logged in users accesses the malicious website this happens: the iframe follows the mouse so that the button is on the mouse. When the user clicks, they click on the iframe.
Now that is very obvious - the user can see the iframe, but that's one change away: style={{display: 'none', ...}}
. For the sake of the demo I used style={{opacity: '0.1', ...}}
(otherwise you would see nothing interesting):
Clickjack prevention middleware
The solution is simple: to set iframe embed policy for your website: adding django.middleware.clickjacking.XFrameOptionsMiddleware
to settings MIDDLEWARE
and X_FRAME_OPTIONS = 'SAMEORIGIN'
will result in X-Frame-Options
header with value of SAMEORIGIN
, and modern browsers will then prevent your website from being embedded on other websites.
Does your website have security vulnerabilities?
Over time it's easy for security vulnerabilities and tech debt to slip into your codebase. I can check that for you at django.doctor, or can review your GitHub PRs:
Or try out Django refactor challenges.
Posted on December 11, 2020
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