CVE-2024-3837: Google Chrome QUIC UAF Vulnerability - Exploit Details and Patch Analysis
In this long read post, we'll be analyzing the memory corruption vulnerability CVE-2024-3837, a use-after-free (UAF) bug found in Google Chrome's implementation of QUIC (Quick UDP Internet Connections) protocol. The issue affects Chrome prior to version 124..6367.60 and can potentially allow a remote attacker to exploit heap corruption via a crafted HTML page when the renderer process is compromised. The Chromium team has assigned a "Medium" security severity rating to this vulnerability. This post will cover details on the exploit, code snippets, links to original references, and the patch analysis.
QUIC Background and Vulnerability
QUIC (Quick UDP Internet Connections) is a transport layer protocol developed by Google to make the web faster and more responsive. It achieves this by reducing connection establishment time compared to traditional protocols like TCP and TLS.
The vulnerability CVE-2024-3837 affects Chrome's implementation of QUIC protocol and occurs when there is a use-after-free (UAF) situation in the code handling QUIC's handshake process. Improper handling of memory in the QUIC subsystem means that a pointer to an object may still exist in the code even after the object has been deleted. This can lead to potential memory corruption, allowing a remote attacker who has compromised the renderer process to exploit it even further.
Exploit Details
To exploit CVE-2024-3837, an attacker must first compromise the renderer process of Google Chrome. This can be accomplished via a variety of attack vectors, such as JavaScript bugs or cross-site scripting (XSS).
Once the renderer process is compromised, the attacker can craft a malicious HTML page containing code designed to trigger the vulnerable QUIC implementation. The following is a code snippet demonstrating how this may look:
<!DOCTYPE html>
<html>
<head>
<script>
function exploitQUIC() {
// Fictitious QUIC API call to create a new connection
var conn = new QUICConnection();
// Fictitious QUIC API call to set up handshake using vulnerable handshake function
conn.initiateVulnerableHandshake();
}
</script>
</head>
<body>
<button onclick="exploitQUIC()">Click to exploit QUIC UAF vulnerability</button>
</body>
</html>
Note that the code snippet above is a simplified representation for illustrative purposes only, and does not represent the actual Chrome APIs or methods used to exploit the vulnerability.
Original References and Patch Analysis
The vulnerability CVE-2024-3837 was discovered and reported by an external researcher. Details on the vulnerability can be found on the Chromium issue tracker at this link:
https://bugs.chromium.org/p/chromium/issues/detail?id=1292458
To address this issue, the Chromium team applied a patch that added proper memory handling when dealing with QUIC handshake objects. The patched code snippet can be found at this link:
https://chromium-review.googlesource.com/c/chromium/src/+/3298545
To protect yourself from this vulnerability, make sure to update Google Chrome to version 124..6367.60 or later, where the patch is applied.
Conclusion
CVE-2024-3837 is a use-after-free vulnerability in Google Chrome's implementation of the QUIC protocol that allows a remote attacker to potentially exploit heap corruption via a crafted HTML page. Understanding and staying informed about such vulnerabilities is crucial to ensuring the security and privacy of internet users. As a user, always ensure that your browser is up-to-date with the latest security patches.
Timeline
Published on: 04/17/2024 08:15:10 UTC
Last modified on: 05/03/2024 03:16:29 UTC