One word can break ANY iPhone and stop it connecting to the internet

If you own an iPhone, you need to be very careful what name you give your home Wi-Fi network. That’s because a security researcher has discovered that a bizarre bug inside iOS – the operating system that powers every iPhone model – can completely disable the smartphone’s ability to connect to Wi-Fi if the network has a certain name.

And when we say “completely disable”, we really mean it. If you use this name for your Wi-Fi network, your iPhone will reboot. When it’s turned back on, the Wi-Fi toggle in the Settings menu will be switched to “off” and you’ll be unable to switch it back on.

Not only will you be restricted to mobile internet, but since your Wi-Fi is disabled, you’ll lose a number of useful iPhone features, including AirDrop and AirPlay.

Security researcher Carl Schou was the first person to discover the quirky glitch. The name you can’t use for your Wi-Fi network is: %p%s%s%s%s%n.

Schuo has not revealed how he figured out the baffling bug. However, Apple-centric blog 9To5Mac claims that the string is causing a memory corruption – which triggers a safety procedure built into iOS to kill the entire process. Unfortunately, while that does end the memory corruption, it also disables Wi-Fi for good.

Unless you live with the sort of prankster who thinks this would be a fun thing to do… it does seem unlikely that you’ll run across this very often. We’re sure Apple will be working on a fix for this, but in the meantime, it’s worth swerving any Wi-Fi networks with % symbols in their name.

If you’ve already made the mistake, don’t worry, the bug doesn’t seem to permanently damage your iPhone. It is possible to bring back Wi-Fi on your handset, but you’ll need to reset all of your network settings, which means joining all of your Wi-Fi networks again (so you’ll need to remember those all-important passwords), changes cellular settings and VPN access settings. To do that, head to Settings > General > Reset > Reset Network Settings.