CVE-2025-21253: Microsoft Edge for iOS and Android Spoofing Vulnerability - A Deep Dive

Microsoft Edge is a popular web browser developed by Microsoft for both iOS and Android platforms. It offers enhanced performance, security, and sync features that provide a seamless browsing experience across all devices. However, like any other software, Microsoft Edge is not immune to security vulnerabilities. In this long-read post, we will examine the CVE-2025-21253 vulnerability, which is a spoofing vulnerability affecting Microsoft Edge for iOS and Android.

In essence, the CVE-2025-21253 vulnerability allows an attacker to exploit a weakness in the Microsoft Edge browser to mislead the user into believing that they are visiting a legitimate website when, in fact, they are being directed to a malicious site on the attacker's server. This can lead to phishing attacks, malware installation, and theft of user data.

Patching the vulnerability is critical to ensuring the security and privacy of users

- In this post, we will explore the technical details of the vulnerability and discuss the mitigation steps

Technical Details

The CVE-2025-21253 vulnerability lies in the way Microsoft Edge handles certain types of navigation actions specifically when redirecting users to a different website. An attacker can craft a malicious web page containing a specially designed JavaScript code snippet that triggers the vulnerability when opened in the Microsoft Edge browser.

Here's an example of a code snippet that an attacker can use to exploit the CVE-2025-21253 vulnerability:

  <script>
  function exploitSpoofingVulnerability() {
    window.location.replace("https://www.example.com";);
    history.pushState("", "", "https://www.vulnerable-edge-victim.com";);
  }
 
  window.onload = function() {
    setTimeout(exploitSpoofingVulnerability, 300);
  };
  </script>

In this example, the malicious JavaScript code first navigates the user to a legitimate website (www.example.com) using the location.replace() function but then immediately updates the browser's address bar to display a completely different website's address (www.vulnerable-edge-victim.com) by using the history.pushState() function.

Original References

If you're interested in learning more about this vulnerability and related research, here are some original references that you can consult:

- CVE-2025-21253 - NVD Detail
- Microsoft Security Response Center (MSRC) Security Advisory
- Security Researcher's Blog Post: Breaking the Edge of Trust

Exploitation and Impact

As mentioned earlier, the CVE-2025-21253 vulnerability can be exploited to carry out phishing attacks and steal user data. It can also be chained with other vulnerabilities to perform more extensive attacks on the victim's device and gain unauthorized access.

For instance, an attacker may use the spoofed website to trick the victim into providing sensitive information such as login credentials or credit card information. Similarly, the attacker may also use the vulnerability to redirect the victim to a site hosting malicious code, which can then be executed on the victim's device to compromise their security further.

Mitigation Steps

To protect your devices from the CVE-2025-21253 vulnerability, it is recommended to take the following mitigation steps:

1. Update Microsoft Edge: Microsoft has released an update for Microsoft Edge to addresses this vulnerability (check Microsoft's Security Update Guide). iOS and Android users should update to the latest version of the browser as soon as possible.

2. Enable Browser Security Features: Enable built-in security features like SmartScreen Filter and pop-up blocker in the Edge browser. These features provide an additional layer of protection by warning users about potentially unsafe websites and blocking malicious scripts from executing.

3. Be cautious of suspicious links: Avoid clicking on links sent through emails, text messages, or social media platforms from unknown sources. Malicious links can lead to websites that exploit the CVE-2025-21253 vulnerability.

4. Use anti-malware software: Install and keep anti-malware software up-to-date on your devices to detect and prevent malware infections that may leverage vulnerabilities like CVE-2025-21253.

Conclusion

In this long-read post, we examined the CVE-2025-21253 vulnerability that affects Microsoft Edge for iOS and Android - a spoofing vulnerability with potentially significant consequences for users. We highlighted the technical details, explored original research sources, and discussed the potential exploitation scenarios and their impact. Finally, we presented a set of mitigation steps that can help users secure their browsing experience and protect themselves from this and other vulnerabilities. Ensure that your software stays updated, and always exercise caution when browsing the internet to reduce your risk factors.

Timeline

Published on: 02/06/2025 23:15:08 UTC