In June 2024, security researchers and Apple disclosed CVE-2024-54543, a memory corruption vulnerability affecting multiple Apple platforms, including iOS, macOS, visionOS, Safari, tvOS, and watchOS. This flaw, if left unpatched, could allow attackers to exploit devices by tricking users into viewing malicious web content.

In this long post, we’ll break down what CVE-2024-54543 is, who was at risk, how attackers might exploit it, and—most importantly—how Apple fixed it with improved memory handling. We’ll use straightforward language, provide easy code snippets for understanding the concept, and link to official reference materials.

What Is CVE-2024-54543?

CVE-2024-54543 is a memory corruption vulnerability in Apple’s web rendering engine—used in Safari and other system features that handle web content.

What Could Happen?

If a user visited a hacker-designed web page in Safari or any app that loads web content (even an in-app browser), malicious code inside that page could trigger memory corruption. At best, this might just crash the app or browser. At worst, a skilled attacker could run code on your device without you knowing—potentially stealing data or installing other malware.

Understanding Memory Corruption

Memory corruption happens when a program accesses memory outside what it’s supposed to, often due to bad handling of pointers or buffer sizes in languages like C or C++. This can be triggered deliberately with crafted input—a technique attackers have mastered.

Let’s look at a simplified pseudo-code example of how such vulnerabilities look in real life

// Vulnerable code (conceptual)
char buffer[256];
strcpy(buffer, userSuppliedString); // No size check!

If userSuppliedString is longer than 256 characters, it will overwrite memory past the end of buffer—dangerous!

Hacker creates a malicious web page exploiting the bug.

2. User visits the page in Safari, visionOS, an Apple TV browser, or any system component using WebKit.

Example Exploit Proof-of-Concept (PoC) Snippet

*Note: The real exploit specifics were not public, but here's a safe, educational pseudo-JavaScript snippet showing how malformed input might be delivered via web content:*

// Hypothetical sketch of malicious content
let longString = "A".repeat(10_000);    // Overly long string
document.write("<img src='data:image/png;base64," + btoa(longString) + "'>");

When a vulnerable browser processes this, the backend code handling the image may not check boundaries—leading to memory overflow.

Real-world exploits are complex and usually not publicly documented—always avoid using any real exploits unless for authorized ethical research.

Apple’s Fix: Improved Memory Handling

The good news: Apple fixed CVE-2024-54543 by tightening memory management in affected system components. This means:

- Functions that once copied, read, or wrote to memory without proper checks are now more careful—likely adding bounds checks, using safer APIs, or preventing dangling pointers.
- The same web content that could exploit old versions will no longer work in 2.2/18.2/11.2/15.2 (latest).

Here’s how safer memory code might look (again, in C for illustration)

// Fixed code using safe copying
strncpy(buffer, userSuppliedString, sizeof(buffer) - 1);
buffer[sizeof(buffer) - 1] = '\'; // Null-terminate to avoid overflow

macOS Sequoia 15.2

*Don’t delay! Unpatched devices are easy targets for drive-by attacks via malicious web content.*

Until you’re updated:

Official References

- Apple Security Updates (CVE-2024-54543)
- NVD Entry for CVE-2024-54543
- Apple Update Release Notes
- WebKit Security Documentation

Conclusion

CVE-2024-54543 is a prime example of the constant race in cybersecurity: attackers find new ways to exploit memory bugs, but Apple (along with the infosec community) patches them fast. This bug could have let hackers compromise devices just by making you visit a web page. The fix? Safer memory handling code.

Make sure your Apple devices are updated—and stay tuned for more coverage on major vulnerabilities.


*This exclusive rundown was made just for our readers—please credit if you share. Stay curious, stay safe!*

Timeline

Published on: 01/27/2025 22:15:14 UTC
Last modified on: 02/05/2025 16:15:41 UTC