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When we talk about web browsers and embedded HTML platforms on Windows, one thing is clear: security is crucial. Microsoft spends a lot of time and money making sure that users are safe from bad actors, especially when you open untrusted content. But sometimes, researchers find ways to bypass these security features. Today, we’ll dive into CVE-2022-24502, a security feature bypass in Windows HTML Platforms, explaining how it works, how it can be exploited, and why it matters.

What is CVE-2022-24502?

CVE-2022-24502 is a vulnerability classified as a security feature bypass bug in the Windows HTML platforms. It was officially disclosed by Microsoft in April 2022 (Microsoft Security Guide – CVE-2022-24502). This vulnerability allows attackers to bypass security restrictions by leveraging flawed logic in the way Windows HTML platforms handle certain content.

Affected Systems:

Microsoft Edge Legacy (not Chromium-based)

> Microsoft’s base description:  
> “A security feature bypass vulnerability exists when Windows HTML Platforms improperly handle certain content.”

At its core:

It allows attackers to execute restricted scripts or access resources that are normally blocked by security restrictions—without the victim’s knowledge.

Attackers Craft Malicious HTML Content:

The attacker creates an HTML file with embedded scripts or content that would normally be blocked by Windows’ built-in protections (like Local Machine Zone lockdown, or cross-domain scripting controls).

User Is Tricked into Opening Content:

The user is convinced (often via phishing) to open this file locally—even double-clicking a file attachment in email or from a USB drive could trigger it.

HTML Platform Misinterprets Security Context:

Due to the vulnerability, Windows HTML Platform (often Internet Explorer’s MSHTML engine or WebBrowser controls in third-party apps) improperly recognizes the file’s trust level and allows script execution or content access.

Restricted Code Runs:

Attackers’ code runs with the same privileges as the user—possibly allowing data theft, code download, or lateral movement in an enterprise setting.

Exploit Example: Crafting The Malicious File

Here’s a basic snippet to illustrate what an attacker might do. Suppose you want to run an ActiveX control from a locally saved HTML file, which is normally restricted by security settings.

<!-- attacker-file.html -->
<html>
  <head>
    <title>Poc for CVE-2022-24502</title>
    <script type="text/javascript">
      function exploit() {
        try {
          // Try creating a restricted ActiveX object (e.g., Shell.Application)
          var shell = new ActiveXObject("Shell.Application");
          shell.ShellExecute("notepad.exe", "", "", "open", 1);
        } catch(e) {
          alert('Blocked: ' + e.message);
        }
      }
    </script>
  </head>
  <body onload="exploit()">
    <h1>Malicious File Exploit Demo</h1>
  </body>
</html>

What should happen:

- Normally, Internet Explorer or Windows HTML would block the creation of Shell.Application, especially for files opened locally.
- With CVE-2022-24502, the feature meant to block this can be bypassed under certain crafted conditions.

Exploitation in the Wild

Unfortunately, CVE-2022-24502 is not a "point-and-click" exploit like zero-click RCEs. However, a skilled attacker can combine it with social engineering and file delivery (phishing emails with attachments, or poisoned USB drives) to run code that would normally be blocked.

Microsoft Patch and Mitigation

Microsoft addressed this bug in their April 2022 Patch Tuesday Updates. Everyone is recommended to install updates immediately.

> Mitigation Tips:
> - Apply the latest Windows security updates.
> - Disable Internet Explorer and remove legacy code dependencies.
> - Limit ActiveX use in web apps and document viewers.

More References

- NVD CVE entry
- Microsoft Security Update Guide – CVE-2022-24502
- Security Tracker Listing

In Closing

CVE-2022-24502 shows that even non-critical “user interaction” bugs can become serious when combined with clever social engineering. If you’re a sysadmin or security enthusiast, double down on patching and user education. If you’re a pentester or developer, review how your apps use Windows HTML controls or embed web content.

Staying aware and up-to-date is the best cure for these bypass vulnerabilities.


If you have more questions, or want to see reverse engineering details and deep-dives of CVE-2022-24502, drop a comment below. Stay safe, and always patch your systems!

Timeline

Published on: 03/09/2022 17:15:00 UTC
Last modified on: 05/23/2022 17:29:00 UTC