The update fixes two zero-day vulnerabilities that can be exploited by attackers to hack iPhones, iPads and Macs. The iOS 15.4.1 update also fixed the battery-drain issue for iPhone users.
The first flaw is in the Intel Graphics Driver, which is tracked as CVE-2022-22674 and allows apps to read kernel memory.
The second vulnerability is an out-of-bounds read issue, which is traced as CVE-2022-22675. An error in the AppleAVD media decoder allows apps to execute arbitrary code with kernel privileges.
Apple has fixed the problem in iOS 15.4.1, iPadOS 15.4.1, and macOS Monterey 12.3.1 update with improved input validation and bounds checking.
Apple’s iOS 15.4.1 update also fixes the problem of unusually fast battery drainage after updating to iOS 15.4. It also fixes braille devices’ unresponsiveness and connectivity problems with made-for-iPhone hearing devices.