Apple recently unveiled a new security feature for its latest iPhones, including the iPhone 17 and iPhone Air. Called Memory Integrity Enforcement (MIE), this technology provides continuous memory safety protection. It’s designed to secure critical areas like the kernel and numerous user processes without slowing down the device. This is made possible by the custom design of the new A19 and A19 Pro chips, which were built with MIE in mind.
The company stated that MIE is built on a strong foundation that includes secure memory allocators and an enhanced version of the Memory Tagging Extension (MTE) in synchronous mode. The system also uses comprehensive Tag Confidentiality Enforcement policies to add another layer of security. This is a significant step toward making devices more resilient against memory-based attacks, which are often exploited by malicious actors using mercenary spyware to target individuals.
MIE’s core technology is Enhanced Memory Tagging Extension (EMTE), which is an upgrade to the original MTE specification released by Arm in 2019. MTE’s purpose is to detect and flag memory corruption flaws. While Google’s Pixel phones have had MTE as a developer option since Android 13, and Microsoft has also introduced similar features in Windows 11, Apple’s implementation is a major advancement. As Google’s Project Zero researcher Mark Brand noted, MTE’s ability to spot memory corruption at the very first sign of a dangerous access is a huge step forward for both diagnostics and security.
Brand also commented that the availability of MTE on a production handset like the new iPhones is a significant milestone. He believes this technology has the potential to make zero-day exploits—new, previously unknown vulnerabilities—much harder for attackers to use. This is because MIE’s approach turns MTE from a simple debugging tool into a robust security feature that offers real-world protection.
Apple explained that MIE provides security against two common types of memory vulnerabilities: buffer overflows and use-after-free bugs. Both of these flaw types can lead to serious memory corruption, making devices vulnerable to exploitation. By proactively preventing these issues, MIE aims to stop highly-targeted attacks before they can even begin.
Reference:
