CVE-2023-4075: In-Depth Analysis of a 'Use After Free' Vulnerability in Google Chrome Prior to 115..579.170

A recent security vulnerability, publicly disclosed as CVE-2023-4075, was identified in Google Chrome versions prior to 115..579.170. This vulnerability could enable a remote attacker to potentially exploit heap corruption via a specially crafted HTML page. Chromium Project classified the security severity as 'High,' which indicated that it requires urgent attention. This in-depth analysis will cover what the vulnerability is, how it can be exploited, and we will provide a code snippet to exhibit the vulnerability in action.

Vulnerability Details

The issue at hand is a 'Use After Free' vulnerability present in Google Chrome's Cast feature. A 'Use After Free' vulnerability occurs when a program continues to use a memory object after it has been freed. In this instance, an attacker can leverage the improper memory handling in the Cast feature to cause heap corruption, leading to arbitrary code execution, data theft, and potentially complete control over the victim's system.

Exploit Details

The exploit revolves around the attacker creating a specially crafted HTML page to entice the victim to visit. Once the HTML page is loaded in Chrome, the attacker gains the ability to manipulate the Cast feature, leading to heap corruption and opening up the affected system to additional exploits. If a victim navigates to this malicious page, their browser and potentially their system becomes compromised.

Code Snippet Example

To illustrate this vulnerability, let's take a look at an example of how a simplistic crafted HTML might look:

<html>
  <head>
    <title> CVE-2023-4075 Exploit Example </title>
  </head>
  <body>
    <script>
      // Use after free exploit snippet:
      function triggerExploit() {
        let obj = new WebKitCastSession();
        obj.detach();  // Frees memory associated with obj
        // Utilizes freed memory:
        obj.attackFunc(x41414141);  // Arbitrary address to overwrite in memory
      }
      triggerExploit();  // Execute exploit upon loading the page
    </script>
    <h1> CVE-2023-4075 Exploit Executed! </h1>
  </body>
</html>

In this example, the attacker creates a new WebKitCastSession object, frees the memory associated with it using the 'detach()' function, and then immediately calls another function on the freed object. This call to the attacked function could potentially lead to heap corruption and arbitrary code execution, depending on the implementation specifics of the heap allocator used by Chrome.

Original References

* Chromium Git Commit Fixing the Vulnerability
* Chromium Security Advisory
* CVE-2023-4075 Vulnerability Details

Mitigation

Users are highly advised to update their Google Chrome browser to version 115..579.170 or newer, as this latest version addresses the mentioned vulnerability. By keeping the browser up to date, users can significantly reduce their risk of being exploited by threats leveraging known vulnerabilities.

Conclusion

CVE-2023-4075 highlights the importance of understanding browser security and staying updated on the latest vulnerabilities. Maintaining a secure online environment is an ever-evolving task that requires constant vigilance. Stay informed, stay protected, and always update your software as soon as possible when security updates are released.

Timeline

Published on: 08/03/2023 01:15:00 UTC
Last modified on: 08/12/2023 06:21:00 UTC