An investigation by Talal Haj Bakry and Tommy Mysk has revealed that backwards-compatible support for HTTP in iOS and Android is allowing data from popular apps such as TikTok to be intercepted and altered.

While most apps have made the transition to HTTPS, the research discovered that TikTok on iOS and Android still uses unencrypted HTTP to download media content. Consequently, TikTok inherits all of the known and well-documented HTTP vulnerabilities.

Apple introduced App Transport Security in iOS 9, requiring all HTTP connections to use encrypted HTTPS. Google similarly changed the default network security configuration in Android Pie to block all plaintext HTTP traffic. HTTP vulnerabilities still exist, however, since Apple and Google continue provide a way for developers to opt-out of HTTPS for backwards-compatibility.

We tricked #TikTok to connect to our fake server. We hijacked the timeline so the app shows spam videos about #COVID19#Security #Cybersecurity #Hacking

For more on this: https://t.co/0e7RGyleIW pic.twitter.com/49BbkYbunq — Mysk (@mysk_co) April 13, 2020

The investigation proved that it is possible to successfully intercept TikTok traffic and fool the app to show fake videos as if they were published by popular and verified accounts. Any router between the TikTok app and TikTok’s servers can easily expose a user’s watch history, and change profile photos and videos. While only users connected to the router will see the malicious content, the research suggests that if a popular DNS server was hacked to include a corrupt DNS record, media data could be changed on a large scale.