Recently, a significant security vulnerability, designated as CVE-2023-4069, has been discovered in the V8 JavaScript engine used by Google Chrome. This vulnerability permits a remote attacker to potentially exploit heap corruption through a specially crafted HTML page. According to Chromium's security team, the issue's severity is labeled as "High."

In this long read post, we'll examine the details of CVE-2023-4069, including the nature of the vulnerability, how it can be exploited, and what developers and users should do to protect against it. We will also provide some code snippets and links to original references for better understanding.

Vulnerability Details

CVE-2023-4069 is a type confusion vulnerability that affects the V8 JavaScript engine, which is the core component responsible for executing JavaScript code in Google Chrome. Specifically, the vulnerability pertains to a failure in handling object type information by the V8 engine, leading to incorrect memory access operations and eventually, heap corruption.

The following code snippet demonstrates an instance of type confusion arising from this vulnerability:

// Sample code illustrating type confusion vulnerability

function vulnerableFunction(obj) {
    if (typeof obj !== "object") {
        throw new Error("Invalid input type!");

    // ... perform some operations on obj

    return obj.someProperty;

const maliciousInput = new Proxy({}, {
    get(target, prop) {
        if (prop === "someProperty") {
            return 42;

        return target[prop];


In this example, a malicious input is crafted using JavaScript's Proxy object, which allows control over the internal behavior of an object, such as property access. A specifically designed proxy object tricks the V8 engine into believing that the accessed property is of a different type, causing the engine to incorrectly handle the memory allocation.

For a complete understanding of the vulnerability, it is crucial to consult the official sources

1. Chromium Security Advisory:
2. V8 GitHub Repository:
3. CVE-2023-4069 Details:

Exploit Details

To exploit the CVE-2023-4069 vulnerability, an attacker must create a malicious HTML page containing specifically crafted JavaScript code that triggers the type confusion. When an unsuspecting victim opens this page in Google Chrome, the V8 engine incorrectly processes the manipulated type information, leading to heap corruption.

Heap corruption may enable an attacker to execute arbitrary code within the context of the vulnerable application (Google Chrome) or, at the very least, cause the application to crash, resulting in a denial of service (DoS) condition.

Mitigation and Prevention

Google Chrome has released version 115..579.170, which addresses and resolves the CVE-2023-4069 vulnerability. Users should promptly update their browsers to this latest version to protect against potential exploitation. To update Google Chrome, users can visit chrome://settings/help and follow the directions provided.

Developers should also closely monitor the V8 GitHub repository for any additional security updates or patches that may become available in the future.


In summary, CVE-2023-4069 represents a significant security risk for users of Google Chrome. By understanding the nature and implications of the vulnerability, taking necessary precautions, and diligently updating their browsers, users can greatly reduce the potential for harm. Furthermore, developers should remain vigilant in monitoring the V8 GitHub repository and other relevant sources for any supplemental information or updates related to this issue.


Published on: 08/03/2023 01:15:00 UTC
Last modified on: 08/12/2023 06:19:00 UTC