CVE-2024-27859 - Apple’s Memory Bug That Let Hackers Run Code Through Your Browser

In March 2024, Apple released a security update for several of its main operating systems including iOS, iPadOS, macOS, tvOS, watchOS, and even visionOS. One of the prominent bugs squashed was CVE-2024-27859 — an urgent, behind-the-scenes flaw that could let attackers run whatever code they wanted just by tricking you into loading a nasty web page. This article breaks down what this vulnerability means, how it worked, and how you can keep your Apple device safe.

What’s CVE-2024-27859?

CVE-2024-27859 is a memory handling bug found in Apple’s WebKit, the open-source engine that powers Safari and web browsing across Apple platforms. In simple words, if a hacker could lure you to a specially crafted website, they could exploit this bug and make your device do things you never intended — like run malicious software, steal data, or hijack your session.

Here’s the official advisory from Apple:
https://support.apple.com/en-us/HT214090

> Impact: Processing web content may lead to arbitrary code execution.
> Description: The issue was addressed with improved memory handling.

macOS Sonoma 14 users (Macs)

If you haven’t updated to iOS/iPadOS 17.4, macOS Sonoma 14.4, tvOS 17.4, watchOS 10.4, or visionOS 1.1, your device is still vulnerable.

How Did the Exploit Work? (Explained Simply)

While Apple didn’t publish the deep technical details, clues from the update suggest that improper memory handling in WebKit, like use-after-free or buffer overflow, could give hackers code execution powers.

You visit this website in Safari (or any app that uses WebKit).

3. The browser mishandles memory, letting the attacker *trick the system* and get control — they could run their code, steal info, or worse.

Example Proof-of-Concept (PoC)

Here’s a generic code snippet showing how WebKit bugs like this get exploited. (Note: This is NOT weaponized code! It’s an example):

// Hypothetical: Triggering use-after-free by abusing a vulnerable object in WebKit
let victimObj = new SomeWebKitObject();

function sprayMemory() {
    let arr = [];
    for (let i = ; i < 10000; i++) {
        arr.push(new Array(100)); // Fills memory with predictable data
    }
}

victimObj.onEvent = function() {
    // This may cause the object to be freed but still used later (use-after-free)
    sprayMemory();
}

triggerVulnerability(victimObj);

Note: Actual exploits are much more complex, but this is the basic idea.

Apple Security Release Notes

https://support.apple.com/en-us/HT214090

WebKit Bug Tracker

(May publish the specifics later) https://webkit.org/security/

The bug itself was likely related to dangling pointers or improper memory cleanup — classic tricks attackers use to hijack browsers.

What Should You Do?

Update your device right now.

Here’s how

- Go to Settings > General > Software Update on iPhone/iPad/Apple Watch.

All Apple platforms have released fixed versions as below

- iOS/iPadOS 17.4

Real-World Risks

Bugs like CVE-2024-27859 are a favorite target for spyware makers and hackers because a victim only needs to visit a malicious website — no other clicks needed. Attackers could:

Conclusion

CVE-2024-27859 is another reminder that web browsers are complicated and under constant attack. Even big companies like Apple find dangerous memory bugs in their code. The fix here was to tighten up how memory is handled, so rogue sites can’t sneak in hidden commands. If you haven’t updated your Apple devices, do it — this is the kind of bug attackers love to exploit.

Timeline

Published on: 02/10/2025 19:15:37 UTC
Last modified on: 03/03/2025 16:52:20 UTC