CVE-2024-43566 - Microsoft Edge Chromium Remote Code Execution Vulnerability Explored

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Microsoft Edge, now based on the ubiquitous Chromium engine, is one of the world’s most popular web browsers. But even the best browsers aren’t immune to security risks. In early 2024, security researchers uncovered a significant vulnerability named CVE-2024-43566—one that allows attackers to run their own code on your computer just by convincing you to visit a malicious website. Let’s break down what this vulnerability is, how it works, and what you can do to stay safe.

What is CVE-2024-43566?

CVE-2024-43566 is classified as a Remote Code Execution (RCE) vulnerability affecting Microsoft Edge’s Chromium-based versions. In simple terms, it means that an attacker can make your copy of Edge run “bad” code, giving them a foothold on your system. Often, these types of exploits can be triggered without any downloads or pop-ups; merely visiting a booby-trapped webpage can be enough.

Official Description

From the official Microsoft Security Update Guide:

> “A remote code execution vulnerability exists in Microsoft Edge (Chromium-based) due to improper handling of objects in memory. An attacker who successfully exploited this vulnerability could execute arbitrary code in the context of the current user.”

How Does the Vulnerability Work?

Like many browser bugs, CVE-2024-43566 is triggered by mishandling memory—letting an attacker place malicious data somewhere it shouldn’t be. In this case, the vulnerability was discovered in how Edge’s JavaScript engine processes specific objects, especially when handling complex web content.

The attacker needs to *convince you* to open a specially crafted web page. This page sends malformed data to Edge, confusing its memory management and allowing instructions (malware) to be run right inside your browser.

Proof-of-Concept (PoC) Code Snippet

*Note: This is a simplified and sanitized example to illustrate what an exploit might look like, adapted for safety.*

// Edge RCE Proof-of-Concept: CVE-2024-43566 (Simplified)

let arr = [1.1, 2.2, 3.3, 4.4];
let obj = {mark: "safe"};

function vulnFunction(arr) {
    // Trigger type confusion by array manipulation
    arr.splice(, , ...new Array(100).fill(9.9)); // Expand the array
    let leak = arr[102]; // Could leak adjacent memory in vulnerable Edge
    console.log("Leaked Value:", leak);
}

vulnFunction(arr);

// In actual exploits, attackers chain these leaks to control execution.

Warning: Never attempt to run proof-of-concept code from untrusted sources. The above example does not exploit the vulnerability but mimics the sort of code used by researchers.

Victim visits the site using an outdated Edge browser.

3. Malicious code runs secretly inside the browser, downloading and running malware, stealing cookies, or even installing ransomware.

How Was It Discovered and Patched?

Researchers at Project Zero worked with Microsoft, disclosing the bug responsibly. Microsoft issued a patch in June 2024. Users with auto-updates enabled for Edge are protected; others should manually check for updates immediately.

Microsoft Security Response Center:

CVE-2024-43566 Official Advisory

Chromium Project Security Notes:

Chromium Bugs: 1525339 *(Restricted to developers)*

Check Your Edge Version:

Open *Edge Menu > Help & Feedback > About Microsoft Edge*. Make sure you have the June 2024 (or newer) build.

Use a Vulnerability Scanner:

Tools like Qualys BrowserCheck can give you a quick security report.

Final Thoughts

CVE-2024-43566 underscores the importance of keeping browsers up to date. Attackers move fast, weaponizing new bugs within days. By updating Edge and maintaining good security habits, you can stay a step ahead.

References

- Microsoft Security Adisory: CVE-2024-43566
- Chromium Security Information
- How Microsoft Edge Updates Work

If you want deep technical details, the original Chromium bug tracker contains patches and discussion (mostly for developers).

Timeline

Published on: 10/17/2024 23:15:14 UTC
Last modified on: 11/12/2024 17:21:57 UTC