Apple has released security updates to address a persistent denial of service (DoS) vulnerability (CVE-2022-22588) dubbed doorLock that would altogether disable iPhones and iPads running HomeKit. Apple has addressed this severe issue in iOS 15.2.1 and iPadOS 15.2.1. Devices that received security updates include iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation).

More information on vulnerability and updates is available in Apple security advisory - iOS 15.2.1 and iPadOS 15.2.1.