In this long-read post, we'll be diving deep into the issue of insufficient validation of untrusted input in Intents in Google Chrome on Android, specifically in versions prior to 106..5249.62, as identified by the CVE-2022-3317 report. We'll be understanding what this vulnerability is all about by examining a code snippet, exploring the exploit details, and providing links to original references on the subject. So, let's get started!

Understanding the Issue

CVE-2022-3317 revolves around a security issue in Google Chrome on Android devices, where a remote attacker can bypass navigation restrictions by crafting a malicious HTML page. This vulnerability is due to insufficient validation of input in Intents in the browser, which ultimately results in a low-severity security risk as classified by Chromium security.

The Code Snippet

Let's have a look at a generalized code snippet, which showcases how a remote attacker can exploit this vulnerability in Chrome via a crafted HTML page. Note that this is an example strictly for educational purposes and we do not endorse using it for malicious purposes.

<!DOCTYPE html>
<html>
  <body>
    <h1>Malicious Page</h1>
    <script>
      // Create an Intent with an invalid URL
      var intent = new URL("intent:#Intent;action=android.intent.action.INVALID_URL-Chrome://malicious.example.com;end");

      // Binding the event to an element on the page
      document.getElementById("trigger").addEventListener("click", function (e) {
        e.preventDefault();

        // Trigger the Intent with invalid URL
        window.location = intent;
      });
    </script>
  </body>
</html>

As illustrated in the snippet above, a remote attacker can create an invalid URL by combining a malicious intent with a standard URL. When a user interacts with the page, the invalid URL triggers the intent, bypassing the in-built navigation restrictions in Chrome.

The page is designed to replace a legitimate URL with the invalid URL.

3. When the user interacts with a specific element in the crafted page, the invalid URL is triggered through an intent.
4. As Chrome does not have a validation system in place for it prior to version 106..5249.62, the navigation restrictions are bypassed, and the attacker's malicious actions can be executed.

For more insights into CVE-2022-3317, you can refer to the following original sources

1. CVE-2022-3317 Details on NIST National Vulnerability Database (NVD)
2. Chromium Issue Tracker: Insufficient Validation of Untrusted Input in Intents
3. Google Chrome Releases Blog: Stable Channel Update for Desktop

Mitigating the Vulnerability

To protect your Android device from this vulnerability, make sure to update your Google Chrome browser to the latest version (106..5249.62 or later). By doing so, you'll be ensuring that the insufficient validation issue for untrusted input in Intents has been patched, and your device is no longer susceptible to this specific exploit.

In conclusion, CVE-2022-3317 underlines the importance of regularly updating and patching web browsers, as vulnerabilities can be quickly exploited by threat actors to gain unauthorized access. By staying vigilant and keeping your software up-to-date, you can continue to enjoy safe browsing experiences with Google Chrome on your Android device.

Timeline

Published on: 11/01/2022 20:15:00 UTC
Last modified on: 08/08/2023 14:22:00 UTC