In a world’s first, a security researcher made a discovery that some Wi-Fi networks containing the percent sign (%) as part of their names have the power to shut off the Wi-Fi on iPhones and other iOS tech. Carl Schou is the researcher who found this bug and he tweeted about it recently.
Carl mentioned in his tweet that if someone brings an iOS based device in close proximity of a Wi-Fi network with the name %secretclub%power, the device will lose its ability to use Wi-Fi or any such feature. The bug is so bad that resetting the network settings doesn’t help at all and the device continues to render Wi-Fi service unusable. Few weeks back, Schou and his non-profit group Secret Club had disclosed that when an iPhone is having a connection with a network with SSiD name %p%s%s%s%s%n, a bug would cause the device’s networking stack to disable its Wi-F along with other networking features like AirDrop becoming unusable.
9to5 Mac offered a potential clarification for the odd bug: the ‘%[character]’ syntax is regularly utilized in programming languages to arrange variables into an output string. In C, the ‘%n’ specifier intends to save the quantity of characters composed into the organization string out to a variable passed to the string design function. The Wi-Fi subsystem likely passes the Wi-Fi network name (SSID) unsanitized to some internal library that is performing string formatting, which thusly causes an arbitrary memory write and buffer overflow. This will prompt memory debasement and the iOS watchdog will kill the process, subsequently successfully handicapping Wi-Fi for the user. 9to5 Mac also informed that the bug can probably be kept away by not interfacing with Wi-Fi networks with percent sign in their names.