CVE-2024-12692: Type Confusion in V8 Engine Leads to Heap Corruption in Pre-131..6778.204 Google Chrome

A high severity vulnerability identified as CVE-2024-12692 has been discovered in Google Chrome web browser versions prior to 131..6778.204. This vulnerability arises due to type confusion in the V8 engine, allowing remote attackers to potentially exploit heap corruption via a specially crafted HTML page. In this long-read post, we will delve into the technical details, code snippets, and original references, providing an in-depth look at how this vulnerability affects Chrome users and how it can be exploited.

Background

The V8 engine, an integral component of Google Chrome, is responsible for compiling and executing JavaScript code within the web browser. Type confusion occurs when the V8 engine misinterprets one data type as another, leading to unintended behavior within the application. In this case, type confusion can result in heap corruption, potentially allowing an attacker to execute arbitrary code remotely.

Exploit Details

Through a specially crafted HTML page that triggers the type confusion in the V8 engine, an attacker can exploit heap corruption in Chrome. To demonstrate, let's look at a hypothetical code snippet that would cause this issue:

// Hypothetical vulnerable code in V8 Engine

class ConfusedTypeA {
  constructor() {
    // Dummy data member
  }
}

class ConfusedTypeB {
  constructor() {
    // Another dummy data member
  }
}


function triggerTypeConfusion(arr) {
  // Type confusion occurs here, potentially leading to heap corruption
  return arr[];
}

// Create an array with elements of the confused type
let confusedArray = [new ConfusedTypeA(), new ConfusedTypeB()];

// Trigger the type confusion
let result = triggerTypeConfusion(confusedArray);

In the above example, it may seem that the triggerTypeConfusion() function expects an array of ConfusedTypeA instances, but we're passing an array containing mixed instances of both ConfusedTypeA and ConfusedTypeB. This triggers the type confusion, leading the V8 engine to misinterpret the data type of the ConfusedTypeB instance and potentially causing heap corruption.

Original References

- The Chromium Project's official advisory for this vulnerability is available here, which categorizes the security severity as "High".
- The CVE entry for CVE-2024-12692 can be found in the NIST National Vulnerability Database (NVD).

Mitigation

To mitigate this vulnerability and protect against potential exploits, users are strongly urged to update their Google Chrome browser to version 131..6778.204 or later. This update contains a patch that resolves the type confusion issue within the V8 engine, thereby preventing heap corruption.

Conclusion

In conclusion, CVE-2024-12692 is a high severity vulnerability in the V8 engine present in Google Chrome versions prior to 131..6778.204. This vulnerability, caused by type confusion, can lead to heap corruption and potentially be exploited by remote attackers by crafting a malicious HTML page that triggers the vulnerability. Users are advised to update their browsers to the latest version to mitigate this issue and protect against potential exploits.

Timeline

Published on: 12/18/2024 22:15:05 UTC