Yep. I also learned that too when watching Bauhinia team members' using this to solve a CTF challenge :p It is a multi-series CTF that you get shell from first a ROP chain to system, but you are effectively jailed from running anything but bash, so the only thing you can use is read and cat, and they used the cat /dev/tcp, then redirected it to a pseudo-tty, and read the content of the pseudo-tty in order to get the URL to the inner system. The flag, there it is.