This was passed down in tech reports from our higher military organizations while I was serving, along with official orders to never use the app, since it’s a huge security vulnerability.

I retired 2 years ago, so I no longer have access to those reports. However, here are a few things I was able to scrounge up on the civilian side of things:

https://www.androidcentral.com/tiktok-was-found-be-bypassing-androids-built-protections-and-sneakily-tracking-users

https://gizmodo.com.au/2022/07/tiktok-app-phone-access/

https://www.malwarebytes.com/blog/news/2022/10/tiktoks-secret-operation-tracks-you-even-if-you-dont-use-it

https://www.wired.com/story/tiktok-data-privacy/