https://www.bleepingcomputer.com/news/security/iphone-bug-breaks-wifi-when-you-join-hotspot-with-unusual-name/

​A new iPhone bug has come to light that breaks your iPhone's wireless functionality by merely connecting to a specific WiFi hotspot.

Once triggered, the bug would render your iPhone unable to establish a WiFi connection, even if it is rebooted or the WiFi hotspot is renamed.