I'm thinking about buying a WWAN card for my laptop (like this one here), as it is more convenient to use than USB tethering. However, I'm concerned about the security risk that comes with such a card as it is connected via PCIe.
What if there is a security vulnerability on the modem firmware running on the card? What is the maximum damage an attacker could possibly do? Can the card access memory of the host system?
Edit: I'm using Linux, and the data sheet says the card will use USB 3.0 on all systems but Windows 10. However, it is still plugged in that PCIe/M.2 slot.