A new bug in Apple's iOS mobile operating system can freeze apps and reboot iPhones through text messages, causing temporary denial of service headaches for users worldwide.

The bug is caused byiOS not handling Arabic characters encoded with the Unicode standard - used for non-Latin scripts - properly.
Uses on internet forum Reddit reported several apps on iOS are affected, including iMessages, Mail and the third-party Whatsapp messaging program. Apps can freeze, and in some cases, the messages can cause iPhones to reboot.
The flaw also affects Apple Watch and can reboot the wearables, according to user reports.
Apple acknowledged the bug and said it was working on a fix to be deployed via a software update.
If a message with the malicious Unicode freezes iMessages, users suggest sending another message to the affected device, either via a phone, a Mac computer, the Siri personal assistant, or the share sheet feature in apps.
Turning off lock screen notifications for messages on iPhones and Apple Watch also stops pranksters from rebooting devices.