iOS Instagram and Facebook app render all third party links
1 min
The iOS Instagram and Facebook app render all third party links
The iOS Instagram and Facebook app render all third party links and ads within their app using a custom in-app browser. This causes various risks for the user, with the host app being able to track every single interaction with external websites, from all form inputs like passwords and addresses, to every single tap.
What does Instagram do?
- Links to external websites are rendered inside the Instagram app, instead of using the built-in Safari.
- This allows Instagram to monitor everything happening on external websites, without the consent from the user, nor the website provider.
- The Instagram app injects their JavaScript code into every website shown, including when clicking on ads. Even though the injected script doesn’t currently do this, running custom scripts on third party websites allows them to monitor all user interactions, like every button & link tapped, text selections, screenshots, as well as any form inputs, like passwords, addresses and credit card numbers.
Why is this a big deal?
- Apple actively works against cross-host tracking:
- As of iOS 14.5 App Tracking Transparency puts the user in control: Apps need to get the user’s permission before tracking their data across apps owned by other companies.
- Safari already blocks third party cookies by default
- Google Chrome is soon phasing out third party cookies
- Firefox just announced Total Cookie Protection by default to prevent any cross-page tracking
- Some ISPs used to inject their own tracking/ad code into all websites, however they could only do it for unencrypted pages. With the rise of HTTPs by default, this isn’t an option any more. The approach the Instagram & Facebook app uses here works for any website, no matter if it’s encrypted or not.