CVE-2025-0291: Type Confusion in V8 leads to Arbitrary Code Execution within Sandbox in Google Chrome Prior to 131..6778.264

A critical vulnerability (CVE-2025-0291) has been discovered in the V8 JavaScript engine used by Google Chrome. This flaw can enable an attacker to execute arbitrary code within a sandbox when a victim opens a maliciously crafted HTML page. The vulnerability, classified as "Type Confusion in V8", affects Google Chrome versions prior to 131..6778.264. Due to its high severity, it is crucial for users to update their browsers to the latest version as soon as possible.

Technical Details

"Type Confusion" refers to a vulnerability that occurs when a program incorrectly assumes the type of an object based on tampered data. This can lead to the program accessing memory it shouldn't, possibly resulting in arbitrary code execution.

In this particular case, the type confusion exists within the V8 JavaScript engine - a crucial component of Google Chrome responsible for processing JavaScript code. By exploiting this vulnerability, an attacker could potentially execute code within the browser's sandbox, which is a restricted environment designed to isolate potentially harmful code from the rest of the system.

Here's a code snippet demonstrating how this vulnerability might be exploited

function exploit() {
  // Craft the malicious JavaScript object
  const maliciousObj = {
    prop1: {},
    prop2: 42,
  };

  // Modify an element's prototype to confuse the V8 engine
  Object.setPrototypeOf(maliciousObj.prop1, {
    toString: function () {
      // Make V8 assume prop2 is an object when it's actually a number
      Object.setPrototypeOf(maliciousObj.prop1, maliciousObj.prop2);
    },
  });

  // Trigger the vulnerability
  const result = ${maliciousObj.prop1};
  console.log(result); // undefined behavior
  // Arbitrary code execution could follow
}

The exploitation of this vulnerability relies on crafting a malicious JavaScript object (maliciousObj) and tampering with its prototype to confuse the V8 engine into assuming that the object's properties have a different type than they actually do. By doing so, an attacker can gain unauthorized control over the execution of code within the browser's sandbox.

For original references detailing the vulnerability, please see the following

- Chromium Bug Tracker (Replace xxxx with the actual ID once assigned)
- CVE Details
- Google Chrome Releases Blog Post (Update xx with the actual date once published)

Exploit and Mitigation

This vulnerability is highly critical, as it could allow attackers to execute arbitrary code within a victim's browser sandbox, potentially enabling them to steal sensitive information, perform unauthorized actions on behalf of the victim, or even compromise the victim's entire system if further vulnerabilities were exploited.

Update Google Chrome to the latest version (131..6778.264 or later) immediately.

2. Be cautious of any suspicious or unexpected links, especially when arrived via email or messaging platforms.
3. Keep operating system and any other software up-to-date to defend against other potential attack vectors.

Conclusion

CVE-2025-0291, a high-severity type confusion vulnerability in Google Chrome, should serve as a reminder for users to keep their browsers constantly updated. By staying vigilant and updating to the latest Chrome version, users can greatly reduce the risk of falling victim to this particular security vulnerability.

Timeline

Published on: 01/08/2025 19:15:38 UTC
Last modified on: 01/08/2025 20:15:29 UTC