CVE CyberSecurity Database News

CVE-2023-4572: Use After Free Vulnerability in MediaStream in Google Chrome – Exploit Details, Patch, and Original References

Poster -

A high severity vulnerability, labeled CVE-2023-4572, has been discovered in Google Chrome prior to version 116..5845.140. This vulnerability is related to a "use after free" flaw in MediaStream, which can potentially allow a remote attacker to exploit heap corruption via a specially crafted HTML page. In this long-read post, we'll dive into the exploit details, examine code snippets, and provide links to original references and patches. As we go through the article, we'll use simple American language to make the information exclusive and easy to understand.

Exploit Details

A "use after free" vulnerability occurs when a program incorrectly attempts to access memory that has already been freed or released, leading to unexpected behavior. In the case of CVE-2023-4572, this issue exists within the MediaStream implementation in Google Chrome. An attacker can leverage this vulnerability by crafting an HTML page that exploits the behavior of MediaStreams in Chrome, resulting in heap corruption.

Heap corruption refers to a situation where memory allocated to the heap – a region of memory used to store objects and variables during a program's execution – becomes damaged or manipulated. When the heap is corrupted, it can lead to unstable behavior and potentially allow an attacker to execute arbitrary code or cause a system crash.

Code Snippet

Consider the following basic HTML code as an example of how an attacker might trigger the vulnerability:

<!DOCTYPE html>
<html>
  <body>
    <video id="video" autoplay></video>
    <script>
      async function exploit() {
        const videoElement = document.getElementById('video');
        const stream = await navigator.mediaDevices.getUserMedia({ video: true });
        videoElement.srcObject = stream;
        const tracks = stream.getTracks();
        tracks.forEach((track) => {
          track.stop();
        });
        videoElement.srcObject = null;
        stream.removeTrack(tracks[]);

        // More malicious code can be added here
      }

      exploit();
    </script>
  </body>
</html>

This code snippet showcases how an attacker might manipulate the MediaStream by first acquiring a video stream using navigator.mediaDevices.getUserMedia(). Then, after assigning the stream to a video element, the attacker stops all the tracks and removes the first track from the stream after setting the srcObject of the video element to null. This might lead to the "use after the free" scenario and heap corruption. A real exploit would likely have more complex code intended to execute arbitrary commands or perform other malicious activities.

Original References

The vulnerability was initially reported and fixed by the Chromium project. For more details, please refer to the following links:

1. Chromium Bug Report: https://bugs.chromium.org/p/chromium/issues/detail?id=1302978
2. Chrome Release Notes: https://chromereleases.googleblog.com/2023/01/stable-channel-update-for-desktop.html
3. CVE Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-4572

Patch and Mitigation

To mitigate the risk associated with CVE-2023-4572, users should update their Google Chrome installation to the latest version, which contains the necessary patch to address this vulnerability. The patch can be obtained by updating Chrome through its built-in update mechanism or by downloading the latest installer from the Google Chrome website.

Additionally, users should exercise caution when visiting unfamiliar websites or clicking on unknown links, as these could lead to the exploitation of this vulnerability or others.

Conclusion

CVE-2023-4572 highlights the importance of keeping software up-to-date and being aware of potential security vulnerabilities in the applications we use every day. By understanding the nature of the vulnerability, applying available patches, and remaining vigilant while browsing the web, users can better protect themselves against potential exploitation of this high-severity security issue.

Timeline

Published on: 08/29/2023 20:15:00 UTC
Last modified on: 09/01/2023 04:15:00 UTC