Apple wrote:
An attacker within range may be able to execute arbitrary code on the Wi-Fi chip

A stack buffer overflow was addressed through improved input validation.


A hacker is able to penetrate the wifi chip architecture on iOS-based systems, phones and tablets, to which an update is now released to patch this.

Users not running iOS 10.3.1 are encouraged to update now to mitigate this critical vulnerability.

Reference: https://support.apple.com/en-us/HT207688

(NOTE: This information may be expired if accessed later than May 3, 2017)