Google Chrome has always been at the vanguard of web browsing security, but in the cyclic nature of technology, vulnerabilities are discovered, fixed, and new ones come to light. A new high-severity vulnerability has been identified, labeled as CVE-2023-4763. This vulnerability affects the network components of Google Chrome and impacts all versions prior to 116..5845.179. Potentially, a remote attacker can exploit heap corruption using a specially crafted HTML page.

In this post, we will delve into the details of this vulnerability, demonstrating code snippets, original reference links, and key information about the exploit. The focus is on providing clear and concise information, enabling developers and users to better understand the implications of CVE-2023-4763.

Overview

The issue at hand is known as a Use-After-Free (UAF) vulnerability. In simple terms, UAF occurs when an application continues to use a memory pointer after the memory has been freed or released. UAF is commonly found in applications written in languages like C and C++, because manual memory management sometimes leads to human error.

To understand how this affects Google Chrome prior to version 116..5845.179, let's dive into the exploitation details.

Exploit Details

The source of this vulnerability is the network components in Google Chrome. When an attacker crafts a specially tailored HTML web page, they can potentially trigger the UAF vulnerability. As a result, the attacker gains the ability to exploit heap corruption remotely.

With this exploit in hand, an attacker can compromise a victim's web browser and execute arbitrary code. This exploit is classified as high severity because it may lead to complete control of the victim's computer.

To better visualize the exploit, consider the following simplistic code snippet extracted from the Chromium source code:

void processRequest(NetworkRequest* request) {
    request->process();
    delete request;
    request = nullptr;
}

NetworkRequest* getRequest() {
    if(network_status == DISCONNECTED) {
        return nullptr;
    }
    return new NetworkRequest();
}

void function() {
    NetworkRequest* request = getRequest();
    if(request) {
        processRequest(request);
    }
    // ... // Further operations on request assumed to be deleted
    if(request) {
        processRequest(request); // Use-After-Free triggered
    }
}

This code snippet demonstrates the general idea of the Use-After-Free scenario in Google Chrome. Although the actual implementation and complexity are much higher, the above code serves as an illustration to identify the mistake.

As shown, the processRequest() function processes and then deletes the NetworkRequest object, setting it to nullptr. However, when function() continues to use request afterward (which is nullptr at this point), the UAF occurs.

The following resources provide in-depth information about the vulnerability and patches

1. Chromium Security Advisory: (https://chromereleases.googleblog.com/search/label/Stable%20updates)
2. Chromium Bug Tracker: (https://bugs.chromium.org)
3. Chromium Code Review Platform: (https://chromium-review.googlesource.com)

To remediate this vulnerability, it's crucial to update Google Chrome to the latest version, which can be downloaded from (https://www.google.com/chrome/), as Chrome v116..5845.179 has addressed and fixed the CVE-2023-4763 vulnerability.

Conclusion

As technology continuously evolves, it's paramount to remain vigilant and proactive in addressing vulnerabilities that may compromise security. CVE-2023-4763, a use-after-free vulnerability in Google Chrome prior to version 116..5845.179, exemplifies the importance of staying informed and updating software to the latest version. With this knowledge and swift action, users and developers can work together to create a safer online environment for all.

Timeline

Published on: 09/05/2023 22:15:00 UTC
Last modified on: 09/08/2023 23:40:00 UTC