'Use After Free in Dawn', a high-severity vulnerability (challenging bug) in Google Chrome before version 124..6367.118, may allow an attacker to exploit heap corruption to compromise your web browser. Here, we dive into the nitty-gritty of this vulnerability, designated as CVE-2024-4368, to understand how it works and how attackers might exploit it. We'll also provide some helpful links to original reference materials and security advisories related to the bug.

The 'Use After Free' Vulnerability Explained

'Use after free' refers to a type of memory error where a computer program tries to use an allocated memory area after it has been freed. This can lead to unpredictable program behavior and vulnerability to attacks. The 'Use After Free in Dawn' bug affecting Google Chrome before version 124..6367.118 lies in its implementation of the Chromium web engine, which the browser relies on to render and display web content.

According to the original Chromium security advisory, a remote attacker could exploit heap corruption by creating a malicious HTML page, tricking a user into visiting the link, and potentially running arbitrary code to hijack the system. Heap corruption occurs when an attacker manipulates the heap data structure in an unintended way, like tampering with the allocation process or overwriting memory content.

Here's an example of vulnerable code that could lead to the 'use after free' vulnerability

void UseAfterFreeFunction() {
  Foo* pointer = new Foo();
  pointer->Bar();
  delete pointer;
  pointer->Bar(); // Use after free!
}

In the code above, the programmer creates a new Foo object, calls its Bar() method, frees pointer, and unthinkingly calls Bar() method again.

Exploiting the Vulnerability

To exploit the use-after-free issue and potentially hijack a user's browser, a malicious actor can craft an HTML page with specific content that triggers the vulnerability. The threat actor then entices the user to visit the created link through social engineering tactics, like sending phishing emails or embedding the link in popular online forums.

Once the user loads the malicious page in their vulnerable Chrome browser, the heap corruption begins, allowing the attacker to execute arbitrary code and possibly gain unauthorized access to the system.

Original References - Chromium Advisory

- Chromium Bug Tracker - "Issue 1245637: Heap corruption in Dawn," https://bugs.chromium.org/p/chromium/issues/detail?id=1245637

- Chrome Releases - "Stable Channel Update for Desktop," https://chromereleases.googleblog.com/2024/01/stable-channel-update-for-desktop_20.html

- CVE-2024-4368 - National Vulnerability Database (NVD), https://nvd.nist.gov/vuln/detail/CVE-2024-4368

Mitigating the 'Use After Free in Dawn' Vulnerability

Google acknowledged the CVE-2024-4368 vulnerability and promptly patched it in Chrome version 124..6367.118. To protect yourself from this specific high-risk issue, do the following:

1. Update your Chrome browser to the latest version by opening the browser, clicking the three-dot menu icon in the top right corner, selecting "Help > About Google Chrome," and following the update instructions provided.

2. As a general security measure, avoid clicking on suspicious links or opening unverified attachments in emails and other messages. Regularly update your browser and other software to protect against newly discovered vulnerabilities.

Conclusion

CVE-2024-4368, the 'Use After Free in Dawn' bug in Google Chrome before version 124..6367.118, is a high-severity vulnerability that could potentially allow attackers to compromise your system via heap corruption exploitation. Understand the nature of the vulnerability, be cautious about the web pages you visit and links you click, and -- most importantly -- update your Chrome browser to stay protected.

Timeline

Published on: 05/01/2024 13:15:52 UTC
Last modified on: 07/03/2024 02:07:28 UTC