WordPress plugins boost convenience and creativity for site admins. But sometimes, even handy tools can hide dangerous bugs. CVE-2022-3462 is one such flaw, affecting the Highlight Focus plugin (version 1.1 and below). This bug opens doors to Stored Cross-Site Scripting (XSS) attacks, even for admin users who *shouldn’t* be able to run arbitrary HTML.

This deep dive explains the vulnerability, provides a real code example, shows you how exploitation can happen, and lists references for more research.

Plugin Affected: Highlight Focus WordPress plugin (≤ 1.1)

- Vulnerability: Fails to sanitize/escape some settings, so XSS is possible.
- Who Can Attack: High-privilege users (like admins), even if unfiltered_html is disabled (e.g., in a multisite setup).

How the Vulnerability Works

The plugin allows administrators to edit some options/fields. These fields are directly stored and later rendered in the admin interface or front-end — without sanitizing user input.

Usually, WordPress restricts dangerous HTML for all roles except superadmins, especially in multisite installs. But the bug here lets admin-level users inject malicious scripts into the settings, and the plugin will render them unfiltered.

Let's take an example from the actual plugin code (simplified to show the bug)

// Inside the plugin's settings handler
if (isset($_POST['highlight_focus_color'])) {
    update_option('highlight_focus_color', $_POST['highlight_focus_color']);
}

And later, when displaying the settings or applying the style

$color = get_option('highlight_focus_color');
echo "<div style='color: $color;'>Highlighted text</div>";

`html

red; --'>

- This results in:

html
;'>Highlighted text

- When another user visits this page, the browser executes the &lt;script&gt; tag!

---

## Exploit Scenario

1. Attacker has admin rights (maybe in a multisite, but not superadmin and no unfiltered_html).
2. They go to the plugin's settings and inject a payload, e.g.:

"#000;'>

3. The payload gets stored in plugin options.
4. On any frontend or admin page that uses the plugin, the script executes in all users' browsers (including superadmins).
5. Now, the attacker can steal cookies, session tokens, or carry out other actions as the victim.

---

## Proof-of-Concept (PoC)

Here’s a simple exploit:

1. Go to the Highlight Focus plugin’s settings page.
2. In the “Color” setting (or any other unsanitized field), insert:

Why is It a Big Deal?

- This bug bypasses a WordPress protection: untrusted users shouldn’t be able to run JS, even as admins, if unfiltered_html is disabled.

Stored XSS means the payload stays on the site and attacks anyone visiting.

- Multisite setups are especially at risk, because subsite admins should not be able to escalate privileges or attack main site users.

Update the plugin if a patched version is released.

- As a site owner, always keep plugins up-to-date and check the official plugin page for updates.
- Sanitize and escape! If you are writing plugins, always use functions like esc_attr(), esc_html(), or sanitize_text_field() when saving and displaying user data.

How the fix should look

$color = esc_attr( get_option('highlight_focus_color') );
echo "<div style='color: $color;'>Highlighted text</div>";

References & More Reading

- Official Wordfence advisory
- NIST NVD Detail for CVE-2022-3462
- Plugin homepage
- OWASP: Stored XSS Explanation

Conclusion

CVE-2022-3462 is a perfect example of why input sanitization is 100% critical in WordPress development — at every privilege level. A simple oversight can open up powerful attack paths, even for trusted users. If you maintain WordPress sites, update now and check every plugin carefully. If you’re a developer, use WordPress’ escaping functions religiously!

Have questions or want to see more plugin security breakdowns? Leave a comment below!


*This write-up is exclusive and provides a hands-on demonstration for understanding and testing CVE-2022-3462’s impact. Always test responsibly and notify plugin authors of vulnerabilities you find.*

Timeline

Published on: 11/07/2022 10:15:00 UTC
Last modified on: 11/09/2022 20:08:00 UTC