Yes, I know what is UDP, dont you?
It's just the easiest way to send information over internet, implementation from scratch are a few lines of code. Unlike TCP complex stacks
So if you dont want to be hacked, keep it simple. And dont use millions lines of open source code.
A gas station that it uses embedded devices with software made from scratch wont be hacked everyday like it happened recently.
You wont be safe using thousands lines of code of OpenSSL.
You wont be safe using complex TCP/IP stacks.
And so on, and it doesnt matter if it's open source, open source projects can have bugs known by security agencies and unknown publicly, and it can be infiltrated by undercovers who put backdoors disguised as bugs, and Open source community wont see in two years even in biggest famous Open source projects like OpenSSL.
en.wikipedia.org