A security researcher has found that certain Wi-Fi networks with the percent symbol (%) in their names can disable Wi-Fi on iPhones and other iOS devices. Carl Schou tweeted that if an iPhone comes within range of a network named %secretclub%power, the device won’t be able to use Wi-Fi or any related features, and even after resetting network settings, the bug may continue to render Wi-Fi on the device unusable.
A few weeks ago, Schou and his not-for-profit group, Secret Club, which reverse-engineers software for research purposes, found that if an iPhone connected to a network with the SSiD name %p%s%s%s%s%n it would cause a bug in iOS’ networking stack that would disable its Wi-Fi, and system networking features like AirDrop would become unusable.
9to5 Mac offered a possible explanation for the weird bug:
We’ve reached out to Apple to see if it’s working on a fix, and will update if we hear back from them. But as 9to5 Mac notes, the bug can likely be avoided by not connecting to Wi-Fi networks with percent symbols in their names.