A security researcher has discovered a special string of characters which, if used for your WIFI network name, will break the WIFI on your iPhone.
After joining my personal WiFi with the SSID “%p%s%s%s%s%n”, my iPhone permanently disabled it’s WiFi functionality. Neither rebooting nor changing SSID fixes it :~) pic.twitter.com/2eue90JFu3
— Carl Schou (@vm_call) June 18, 2021
As Schou notes, if you name your WIFI network “%p%s%s%s%s%n” and connect to it with an iPhone, iPad or even AirDrop, your WIFI will be disabled and even a reboot will not fix it.
The name reportedly causes memory corruption in the WIFI stack, and the issue does not affect Android devices, meaning until Apple fixes it there is a potential for people to use it to prank iPhone users.
If you find yourself suddenly unable to connect to WIFI, here is the potential fix:
- Navigate to Settings > General > Reset
- Select Reset Network Settings.
This should clear away all the same networks on your device, allowing you to start over again.
Apple will presumably release a fix for the issue in the next iOS 14 update or soon after.