Here’s a funny bug: a security researcher has found that a carefully crafted network name causes a bug in the networking stack of iOS and can completely disable your iPhone’s ability to connect to Wi-Fi.

On Twitter, Carl Schou showed that after joining a Wi-Fi network with a specific name (“%p%s%s%s%s%n”), all Wi-Fi functionality on the iPhone was disabled from that point on.

Once an iPhone or iPad joins the network with the name “%p%s%s%s%s%n”, the device fails to connect to Wi-Fi networks or use system networking features like AirDrop.

The Wi-Fi subsystem probably passes the Wi-Fi network name (SSID) unsanitized to some internal library that is performing string formatting, which in turn causes an arbitrary memory write and buffer overflow.

You should be able to reset all network settings and start over.

This resets all saved Wi-Fi networks on the iPhone (as well as other things like cellular settings and VPN access), thereby removing the knowledge of the malicious network name from its memory. You can then join your standard home Wi-Fi once more..

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