Just got ethernet wired up on a customer board and fired up nmap in default config to check what services are available. After the first few ports I got the following on the serial console (edited down for easier reading):

<err> os: ***** BUS FAULT *****
[...]
<err> os: >>> ZEPHYR FATAL ERROR 0: CPU exception on CPU 0
<err> os: Halting system

Unsurprisingly the SuT (system under test) was unresponsive afterwards and had to be reset.
#DenialOfService through port scan. Wow.
#IndustrieQualität