There’s a new way to break an iPhone this time you can do it with nothing more than a well chosen WiFi SSID.

Connecting to a WiFi network with the name %p%s%s%s%s%n will break your iPhone and render it unable to connect to any WiFi network.

The bug was spotted by reverse engineer Carl Schou according to Bleeping Computer. The engineer explained in a tweet that after changing his personal WiFi’s SSID to %p%s%s%s%s%n he was unable to connect to any WiFi network.

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

One would hope a reboot or renaming the hotspot would solve the issue but alas it doesn’t and you are left without connectivity.

So what is happening here and can you fix it?

The best guess is that the SSID is creating an input parsing issue where iOS is interpreting the % symbols as string-format identifiers. The bug could also be messing up how the operating system interprets the binary translation of the SSID similar to a Chrome bug from a few years ago.

The bug doesn’t appear to affect the Android operating system but we wouldn’t recommend trying it out.

If you unfortunately have a friend who thinks this would be a fun prank to play on you, there is an easy fix.

Head to Settings and then tap General. Tap Reset and then navigate to the Reset Network Settings and tap continue when prompted. You will need to restart your device and reconnect to any networks, barring the problematic one of course.