In the computer world the word "Debug" generally means, it is "temporary" and meant for troubleshooting Unfortunately, Countless Android devices including DVRs, mobile telephones, Android smart TVs, and even tankers are are open to attack after being shipped with a debug port (TCP 5555) left unsecured

In the computer world the word "Debug" generally means, it is "temporary" and meant for troubleshooting Unfortunately, Countless Android devices including DVRs, mobile telephones, Android smart TVs, and even tankers are are open to attack after being shipped with a debug port (TCP 5555) left unsecureds, silently install software, and execute malicious code, without any need for a password.

Android Debug Bridge (ADB) is a feature that allows developers to communicate with an Android device remotely, executing commands, and – if necessary – taking full remote control.

A network worm called ADB.Miner has been seen scanning across the internet to see where TCP port 5555 used by ADB has been left open, in an attempt to create a cryptomining botnet.

https://hotforsecurity.bitdefender.com/blog/tens-of-thousands-of-android-devices-are-leaving-their-debug-port-exposed-20012.html