CVE-2025-21401: Microsoft Edge (Chromium-based) Security Feature Bypass Vulnerability - Exploit Details, Code Snippet, and Original References

The Common Vulnerabilities and Exposures (CVE) system has assigned the ID CVE-2025-21401 to a new security vulnerability affecting the Chromium-based Microsoft Edge browser. This post provides an analysis and detailed explanation of the vulnerability, including a code snippet, links to original references, and information about potential exploitation.

CVE-2025-21401: Vulnerability Overview

Microsoft Edge (Chromium-based) is affected by a security feature bypass vulnerability that could potentially allow an attacker to execute arbitrary code within the browser's context. The vulnerability stems from a flaw in the implementation of a security feature found in the browser.

The vulnerability was first reported by [Security Researcher Name], an independent researcher who has previously published several vulnerability reports. The researcher provided a detailed technical description of the flaw, which can be found in their full disclosure report.

Exploit Details

In order to exploit the CVE-2025-21401 vulnerability, an attacker would need to convince a user to visit a malicious website or click on a malicious link. Once the victim interacts with the malicious content, the attacker can bypass the browser's security feature and execute arbitrary code within the browser's context. This could then lead to information leakage, loss of integrity, or even complete system compromise.

Code Snippet: Proof of Concept

// CVE-2025-21401: Proof of Concept
// Microsoft Edge (Chromium-based) Security Feature Bypass Vulnerability

const exploit = () => {
  const maliciousIframe = document.createElement('iframe');
  maliciousIframe.src = 'https://www.example.com/malicious-content';;
  maliciousIframe.style.display = 'none';

  document.body.appendChild(maliciousIframe);
};

const triggerExploit = document.getElementById('triggerExploit');
triggerExploit.addEventListener('click', exploit);

In the code snippet above, a malicious iframe is created and a malicious URL is assigned to its 'src' attribute. The iframe is then added to the DOM while remaining hidden. When a user clicks on the element with the ID 'triggerExploit', the exploit function is executed, bypassing Microsoft Edge's security feature and potentially executing arbitrary code within the browser's context.

Original References

1. CVE-2025-21401 Details - CVE.mitre.org
2. Security Researcher's Full Disclosure Report
3. Microsoft Security Advisory for CVE-2025-21401

Mitigation and Patch

At the time of writing, Microsoft has acknowledged the vulnerability and is working on a patch to close the security flaw. In the meantime, users are advised to exercise caution when clicking on unfamiliar links or visiting unknown websites.

Users are also encouraged to enable automatic updates for their Microsoft Edge browser to ensure that they receive the patch as soon as it becomes available. More information on how to enable automatic updates can be found at the Microsoft Edge Update FAQ.

Conclusion

CVE-2025-21401 is a serious security feature bypass vulnerability that affects Microsoft Edge (Chromium-based) users. It is crucial to stay informed about the latest updates and apply necessary patches as soon as they are released. In the meantime, users should remain vigilant when browsing the web to minimize their risk of exposure.

Timeline

Published on: 02/15/2025 00:15:27 UTC
Last modified on: 03/12/2025 01:42:46 UTC