[fizlebit]

It is bad if you print from a Linux laptop that uses WiFi isn’t it?

[LZ2DMV]

Only if the machine is directly connected to the internet and the malicious packet doesn't hit a firewall somewhere along the path.

Most laptops connected to Wi-Fi are indeed connected to an AP or a SOHO router that does NAT, so the attacker won't be able to directly reach it and this is a requirement for this to work.

[jonatanheyman]

The attacker can be on the LAN though.

[WhyNotHugo]

Plenty of laptops have a built in modem and this is becoming more ckmmoj every day. Those connect directly to the internet.

NAT only makes a difference if you use. IPv4 only. If you have dual stack, then your host is on the public internet.