With the ever-increasing use of the internet and reliance on web browsers for daily tasks, it's no surprise that attackers continuously seek new ways to exploit vulnerabilities in web browser software. One such vulnerability, CVE-2023-4350, affects Google Chrome on Android devices and has been categorised as a high severity issue. In this detailed post, we explain the ins and outs of this vulnerability and how attackers might exploit it.

Problem Description

CVE-2023-4350 is a security issue in the implementation of the fullscreen feature in Google Chrome on Android devices. Specifically, this vulnerability exists prior to version 116..5845.96 of the Chrome browser. An attacker can exploit this vulnerability by creating a specially crafted HTML page, which, when opened in Chrome on an affected Android device, has the potential to spoof the contents of the Omnibox - the URL bar where users enter website addresses.

This can have severe security implications, as attackers can deceive unsuspecting users into providing sensitive information or interacting with malicious content, under the illusion that they are on a legitimate, trusted website.

Chromium Security Severity: High

This vulnerability has been given a "High" severity rating by Chromium, the open-source web browser project upon which Google Chrome is built. This rating implies that a successful exploit can result in severe data leakage or unauthorized access to sensitive information.

Exploit Details

To demonstrate how an attacker might exploit CVE-2023-4350, let's take a look at a code snippet that showcases a part of the crafted HTML page:

<!DOCTYPE html>
        body {
            margin: ;

        #fake-url {
            position: absolute;
            top: ;
            left: ;
            font-family: Arial, sans-serif;
            font-size: 18px;
            padding: 6px;
            color: #000;
            background-color: #fff;
            border-bottom: 1px solid #ccc;
            z-index: 2;

        #real-content {
            position: absolute;
            top: ;
            left: ;
            height: 100%;
            width: 100%;
            z-index: 1;
<body onfullscreenchange="checkFullscreen();">
    <div id="fake-url">
    <!-- Malicious content goes here -->
    <div id="real-content">
         <!-- User interaction requested -->

In this snippet, the attacker designed a webpage to include a fake URL bar styled to resemble a legitimate URL bar. This can trick the user into believing they are on a different website than the one they're actually visiting, and can potentially lead to socially-engineered attacks or phishing scams.

For more details and information about this vulnerability, you can refer to the following resources

1. Chromium Issue Tracker - Issue 1276289: Omnibox spoofing on Android
2. CVE-2023-4350 - NVD (National Vulnerability Database)


To protect your Android device from this vulnerability, it is essential to update your Google Chrome browser to the latest version (116..5845.96, or later). This will eliminate the issue and reduce the risk of falling victim to an attack. To check your Chrome version, open the app, visit Settings, and then select "About Chrome" in the menu.

Stay vigilant, stay informed, and keep your software up-to-date to protect yourself from the ever-evolving world of cybersecurity threats.


Published on: 08/15/2023 18:15:00 UTC
Last modified on: 08/21/2023 17:27:00 UTC