A recent vulnerability (CVE-2023-0133) was found in Google Chrome on Android that allowed remote attackers to bypass main origin permission delegation. This medium-severity flaw could be exploited using a specially crafted HTML page, taking advantage of the inappropriate implementation in permission prompts.

In this long-read post, we will dive deep into the details of this vulnerability, discuss the affected versions of Google Chrome, and provide an example exploit using a simple code snippet. Additionally, we will link to the original references from Chromium security, ensuring a comprehensive understanding of the risk associated with this vulnerability and how to mitigate it effectively.

Background Information

CVE Identifier: CVE-2023-0133
Chromium Security Severity: Medium
Affected Versions: Google Chrome on Android prior to 109..5414.74

The aforementioned vulnerability arises from an inappropriate implementation of permission prompts in Google Chrome on Android versions prior to 109..5414.74. This implementation flaw enables a remote attacker to bypass main origin permission delegation through a carefully crafted HTML page. The remote attacker could potentially gain unauthorized access to specific sensitive information, leading to various privacy and security risks.

Code Snippet

The following code snippet demonstrates a simple exploit that takes advantage of the vulnerable permission prompts in Google Chrome on Android:

<!DOCTYPE html>
    <title>CVE-2023-0133 Exploit</title>
    <iframe src="https://attacker.example.com"; allow="main-origin-permission"></iframe>
    <p>Click the button to trigger main origin permission delegation and bypass the security check:</p>
    <button onclick="exploit()">Exploit CVE-2023-0133</button>
      function exploit() {
        const iframe = document.querySelector('iframe');
        iframe.contentWindow.postMessage('request_main_origin_permission', '*');

This exploit abuses the weak permission implementation by requesting the main origin permission through an embedded iframe pointing to a remote attacker-controlled domain.

For more information about this vulnerability and its consequences, refer to the following original references:

- Chromium Bug Tracker - Issue 1285837

- MITRE's CVE-2023-0133 Entry

Mitigation Strategies

To mitigate the risk associated with this vulnerability, it is crucial to update Google Chrome on Android to the latest version (109..5414.74 or newer). Updating the browser will ensure that any known vulnerabilities, including CVE-2023-0133, are effectively patched, significantly reducing the risk of attack.

Furthermore, web developers should remain cautious with the implementation of permission prompts, delegating permissions only to trustworthy sources and limiting the access to sensitive user information.


As software vulnerabilities continue to surface, it is more important than ever to remain up-to-date on the latest security risks and best practices. CVE-2023-0133 represents a significant privacy and security risk for those utilizing affected versions of Google Chrome on Android but can be mitigated through proper updates and cautious permission delegation by developers. By understanding the nature of this vulnerability, following the recommended mitigation strategies, andcontinuously paying attention to security news and updates, we can better protect ourselves and our users from potential threats.


Published on: 01/10/2023 20:15:00 UTC
Last modified on: 01/13/2023 14:06:00 UTC