Some weeks after the initial iPhone Wi-Fi bug was found, the security researcher has found another similar issue.
Someone tweeted today that if an iPhone comes in range of a Wi-Fi network named ‘%secretclub%power’, then that iPhone will no longer be able to use Wi-Fi or Wi-Fi related features. That person even says that this bug persists when resetting network settings. It seems the only workaround for this particular issue would be a hard factory reset of the device.
The earlier problem relied on the iPhone encountering a network name with the SSiD “%p%s%s%s%s%n” and the user attempting to connect to it. However, that bug was fixable by resetting iPhone network settings in the Settings app. This new problem appears more severe as it can trigger as soon as the iPhone comes in range of a malicious public Wi-Fi hotspot using that poisoned name.
Obviously the underlying bugs are related as both ‘%secretclub%power’ and ‘%p%s%s%s%s%n’ exploit a string format coding error somewhere in the underlying iOS networking stack.
It seems likely that there are many more variants of bug-inducing network names that use the ‘%s’, ‘%p’ and ‘%n’ character sequences.
From the view of an individual user, the best safety precaution is to simply avoid connecting to Wi-Fi networks that contain percent symbols in their name. Then wait for the inevitable software update where Apple will fix the OS bug that is causing the denial of service.