Lockdown Mode Bypassed in New iPhone Exploit

Security researchers at Calif posted on X that they were able to exploit an iPhone 18 Pro despite Lockdown Mode, a setting that's designed to make your device more resistant to exploits.

The video shows an iPhone 18 Pro, a very recent iPhone model, being exploited using a malicious PDF file that's Airdropped onto the device.

Once they're able to run code, they update the phone to the latest version of iOS as of the writing of this article, 27.2, and show that the malware persists through a software update.

An Apple spokesperson famously claimed "we are not aware of any successful mercenary spyware attacks against a Lockdown Mode-enabled device" in an interview with TechCrunch lauding the effectiveness of the security feature.

Lockdown Mode works by removing features that pose a risk for attacks like attachments and link previews in Messages, certain complex web technologies in Safari, and allowing you to block the now outdated 2G and 3G connectivity in your cellular modem. It also blocks incoming FaceTime calls from people you haven't called in the past 30 days and blocks configuration profiles from being installed, among many other things both documented and undocumented by Apple.

Calif did not release details of how the attack works, merely a video demonstration, with technical details likely coming later when Apple has had time to release a patch and people have had time to install it.

Calif in October released another demonstration showing they had successfully hacked the iPhone through both Signal and iMessage and achieved a persistent jailbreak across reboots.

They also didn't release details of this attack. Still both are very impressive. Apple has put considerable work into hardening the Messages app and the operating system overall via Memory Integrity Enforcement (MIE), a protection designed to prevent memory safety vulnerabilities, one of the most common types of vulnerabilities. MIE is enabled for the kernel and "over 70 userland processes" according to Apple. Signal also enables the feature for their app.

In a previous blog post outlining how they were able to exploit macOS even with MIE enabled, they highlighted how useful AI was for finding an exploit chain:

Mythos Preview is powerful: once it has learned how to attack a class of problems, it generalizes to nearly any problem in that class. Mythos discovered the bugs quickly because they belong to known bug classes. But MIE is a new best-in-class mitigation, so autonomously bypassing it can be tricky. This is where human expertise comes in.

In a later blog post they said:

Given their complexity, rapid evolution, and the limited public discussion of exploitation techniques, we believe modern XNU kernel exploitation is one of the hardest and most interesting benchmarks for AI-assisted exploit development.