Several Android phones appear to be vulnerable to an exploit in the WiFi firmware, allowing an attacker to run malicious code on the WiFi SoC, and even execute code in kernel space. Google patched its Pixel phones and some recent Nexus models, but older models such as the Nexus 5 have no patch available yet. It seems that no attack is known in the wild yet, but if there was one it could spread quickly from device to device.
I have a Nexus 5; what can I do to secure my phone? For now I have WiFi turned off, but that significantly reduces the usefulness of my phone. I'm comfortable running commands with
adb to install drivers, if that's possible. I'm also willing to install another OS, although I'd rather not have to.