An issue exists where an app may be able to modify sensitive kernel state due to a memory out-of-bounds operation. The flaw involves the use of undocumented MMIO (Memory-Mapped I/O) registers in Apple SoCs, which allows attackers to bypass hardware security protections and manipulate protected kernel memory to gain full control of the device. This issue was part of a campaign known as Operation Triangulation, where attackers could deliver a malicious iMessage attachment to compromise a device without any user interaction. There are reports that this issue was actively exploited against iOS versions released before iOS 15.7.1.