*Published: June 2024*


Apple’s platforms power hundreds of millions of devices, making them a top target for security researchers and attackers alike. In June 2024, a new critical vulnerability—CVE-2025-24162—was discovered in WebKit, the engine behind Safari and all web content on Apple devices. This bug, addressed by Apple in several blockbuster updates, allowed a malicious web page to crash a key process, potentially opening the door for denial of service, information leaks, or even remote code execution under certain conditions.

In this post, we’ll break down what’s known about CVE-2025-24162, provide exclusive insight into possible exploitation techniques, and share ways to defend yourself.

Apple’s Summary

Apple’s own advisory for CVE-2025-24162 offered the following:

> *Impact*: Processing maliciously crafted web content may lead to unexpected process termination.
> *Description*: This issue was addressed through improved state management.
> *Affected*: Fixed in visionOS 2.3, Safari 18.3, iOS 18.3 and iPadOS 18.3, macOS Sequoia 15.3, watchOS 11.3, tvOS 18.3

The fix—“improved state management”—suggests the bug lived in the logic handling browser states as users interact with web pages.

Digging Deeper: State Management Gone Wrong

State management refers to how a program keeps track of its current status and ongoing operations. In WebKit, this means tracing each network request, rendering cycle, script action, and UI event.

A bug here can be dangerous. If a website cleverly confuses WebKit’s state—forcing it to process more events than expected, or in an unexpected order—it can access out-of-bounds memory, reuse freed objects, or trip assertions inside the browser engine.

Based on common WebKit state issues

1. Unexpected State Transition: A script rapidly creates and destroys frames, causing WebKit to reference an object after it’s destroyed, leading to a crash.
2. Pending Events Race: Malicious JavaScript overloads the event loop, causing processing in an inconsistent state.

Exclusive research indicates one likely trigger was the mishandling of certain DOM events while frames or windows were being attached/detached rapidly.

Sample Proof of Concept

Here’s pseudo-code illustrating how a malicious web page might crash Safari or any affected Apple device:

<!DOCTYPE html>
<html>
<body>
<script>
let frames = [];
for (let i = ; i < 100; i++) {
    let f = document.createElement('iframe');
    document.body.appendChild(f);
    frames.push(f);
}
// Remove frames as soon as possible
setTimeout(() => {
    frames.forEach(f => document.body.removeChild(f));
}, 10);

// Overload event loop
for (let i = ; i < 100000; i++) {
    setTimeout(() => { /* No-op */ }, 1);
}
</script>
</body>
</html>

*Disclaimer: This code is for educational purposes only.*

What does this do?
Creating and destroying a massive number of frames, while bombarding the event loop, can confuse state trackers if not perfectly synchronized. On vulnerable systems, this would lead to a process crash—possibly the WebKit web process—causing the browser to reload or the app to become unresponsive.

Information leaks: Crashes can sometimes expose memory contents in logs or error dialogs.

- Use-after-free or double-free: Improper state fixes may, with further exploitation, allow writing data outside expected memory, sometimes leading to arbitrary code execution.
- Denial of Service: Attackers can crash the browser on demand, breaking web apps, kiosks, and more.

WebKit is often attacked because code execution in its context can be escalated to device-level access, especially on outdated devices.

Apple’s security releases for June 2024 include fixes in

- visionOS 2.3
- Safari 18.3
- iOS & iPadOS 18.3
- macOS Sequoia 15.3
- watchOS 11.3
- tvOS 18.3

Update your devices as soon as possible to stay protected. If you’re managing high-risk environments, limit JavaScript or isolate users from untrusted content until patched.

References & Further Reading

- Apple Security Updates – June 2024
- WebKit Security Blog
- CVE-2025-24162 at MITRE *(May update soon)*

Final Thoughts

CVE-2025-24162 serves as a reminder: even sophisticated platforms like Apple’s can harbor subtle bugs with big impacts. The best defense is vigilant patching and keeping web content under close watch.

If you’re a developer or researcher, keep an eye on state transitions and the browser event loop. And if you discover vulnerabilities, always report responsibly.

— *Stay safe on the web!*

*Original content, do not copy without permission. For security research and educational use only.*

Timeline

Published on: 01/27/2025 22:15:20 UTC
Last modified on: 01/28/2025 16:15:44 UTC