---

CVE-2023-4762 refers to a significant "Type Confusion" vulnerability discovered in the V8 JavaScript engine used in Google Chrome. This vulnerability affects all versions prior to 116..5845.179 and could potentially allow a remote attacker to execute arbitrary code via a crafted HTML page. Considering the high security severity of this issue, it is crucial for users to understand its implications and the measures needed to mitigate the risk.

Vulnerability Overview

There's a bug in Google Chrome's V8 JavaScript engine that allows an attacker to create a crafted HTML page, which, when executed, may lead to arbitrary code execution. This vulnerability stems from the type confusion, where the V8 engine incorrectly interprets a different data type than intended, leading to unexpected behavior.

The following code snippet demonstrates the possible exploit

// CVE-2023-4762: Type Confusion PoC Exploit
(function () {
  // Create a new array with a size that triggers type confusion
  let arr = new Array(2 ** 32 - 2);

  // Fill the array with objects to potentially overwrite memory
  for (let i = ; i < arr.length - 2; i++) {
    arr[i] = { value: i };
  }

  // Create a forced type confusion scenario
  arr.length = 2 ** 32 - 1;
  arr[arr.length - 1] = {};
})();

1. Official Chromium bug report: https://bugs.chromium.org/p/chromium/issues/detail?id=
2. CVE Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-4762
3. National Vulnerability Database (NVD) entry: https://nvd.nist.gov/vuln/detail/CVE-2023-4762

Exploit Details

The exploit relies on manipulating the V8 engine into misinterpreting data types due to the size of an array. The attacker initially creates an array of objects with a size that is very close to the maximum limit of an unsigned 32-bit integer (2^32 - 2). Subsequently, the attacker maliciously increases the array's length value by one (2^32 - 1), pushing the array's size over the limit. When this occurs, the V8 engine becomes "confused" in handling the malicious array and treats the last item in the array as a different data type than it should.

As a result, an attacker can potentially exploit memory corruption to execute arbitrary code within the browser's context. This could lead to a myriad of consequences, such as stealing user data, injecting malware, or even taking over the user's device.

It is worth noting that to exploit this vulnerability, the user needs to visit the crafted HTML page. Thus, it is essential to follow safe browsing practices and only click on links from trusted sources.

Mitigation Measures

Google has addressed this vulnerability in Google Chrome version 116..5845.179. It is highly recommended that users update their browsers to this version or newer to protect themselves from this exploit.

In conclusion, CVE-2023-4762 is a high-severity vulnerability requiring immediate attention. This vulnerability highlights the importance of staying up-to-date with browser updates and remaining vigilant about the sources of web content to minimize risks.

Timeline

Published on: 09/05/2023 22:15:00 UTC
Last modified on: 09/08/2023 23:37:00 UTC