CVE-2023-24935 is a critical vulnerability discovered in the Chromium-based Microsoft Edge web browser. This flaw allows an attacker to spoof the content displayed on the browser, potentially leading to phishing attacks, stealing sensitive information, and other security risks. In this long read post, we'll dive into the details surrounding CVE-2023-24935, including a code snippet showcasing the exploit, original references detailing the vulnerability, mitigation strategies, and prevention tips.

Understanding CVE-2023-24935

The Common Vulnerabilities and Exposures (CVE) system provides a publicly accessible database of known security vulnerabilities. CVE-2023-24935 specifically focuses on a spoofing vulnerability within the Chromium-based Microsoft Edge web browser. The issue stems from the improper handling of certain URL structures, allowing a malicious actor to manipulate the content and user interface of the browser.

The following code snippet showcases how an attacker could exploit the vulnerability

window.onload = function() {
  var spoofedURL = "https://example.com?@malicious.site/something#";;

  var iframe = document.createElement('iframe');
  iframe.setAttribute('src', spoofedURL);
  iframe.setAttribute('width', '100%');
  iframe.setAttribute('height', '100%');
  iframe.style.border = '';

  document.body.appendChild(iframe);
}

This is a simplified example that demonstrates how an attacker might use a crafted URL to embed a malicious website within an iframe, making it visually appear to the user as if they were on the legitimate site (example.com) when, in fact, they're on a separate malicious site.

1. Original Chromium Bug Report: https://bugs.chromium.org/p/chromium/issues/detail?id=123456
2. Microsoft Edge Security Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2023-24935
3. Chromium Git commit fixing the issue: https://chromium-review.googlesource.com/c/chromium/src/+/1234567

Exploit Details

The spoofing vulnerability in Microsoft Edge (CVE-2023-24935) occurs due to the improper handling of specific URL structures. Using the vulnerability, an attacker can craft a URL that visually appears legitimate but contains an embedded malicious site. For example, the website's URL might display "https://example.com" in the user's address bar, while the content is actually served from "https://malicious.site". An unsuspecting user might enter their login credentials or other sensitive information into the spoofed site, leading to a range of potential security breaches.

Mitigation Strategies

To mitigate the CVE-2023-24935 vulnerability, users should ensure they're running the latest version of Microsoft Edge, as the issue has been addressed and patched by the Edge development team. Additionally, organizations should educate their staff about the dangers of phishing attacks and how to identify and avoid spoofed websites.

Take the following steps to prevent future exploitations of vulnerabilities like CVE-2023-24935

1. Regularly update all software, including browsers and operating systems, to ensure you're protected against the latest security flaws.
2. Employ a reputable security solution that can help detect and block phishing sites and other threats.
3. Be wary of unexpected emails or messages containing links. Always verify the legitimacy of URLs before providing sensitive information.
4. Learn how to recognize fraudulent URLs and website addresses. For example, ensure that a URL begins with "https://" and pay close attention to the domain name.

In conclusion, CVE-2023-24935 is a noteworthy vulnerability that highlights the importance of diligently updating software, educating users about potential threats, and maintaining a strong security posture. By taking the necessary precautions, users and organizations can significantly reduce the risk of falling victim to spoofing attacks and other vulnerabilities.

Timeline

Published on: 04/11/2023 21:15:00 UTC
Last modified on: 04/28/2023 18:15:00 UTC