CVE-2023-3709 - Unauthenticated API Key Disclosure in Royal Elementor Addons – Exploit Details & Mitigation

Discovered: June 13, 2023
Severity: High
Affected Plugin: Royal Elementor Addons (WordPress)
Affected Versions: ≤ 1.3.70
Vulnerable Feature: MailChimp Block
Status: Patch available (Update to latest version)

What is CVE-2023-3709?

CVE-2023-3709 is a vulnerability affecting the Royal Elementor Addons plugin for WordPress, which allows attackers to steal your site’s MailChimp API key if you use the MailChimp block — with no authentication required.

This happens because versions up to and including 1.3.70 place the API key directly into the source code of the pages where the block is enabled. Anyone can simply view the page’s source and grab your confidential MailChimp API key—this puts both your emails and your reputation at risk.

How the Exploit Works

When you add a MailChimp signup form (using the Royal Elementor Addons MailChimp block) to any page, the plugin outputs the MailChimp API key in the page source so the form can communicate with MailChimp.

Problem: The key is visible to anyone, not just admins or logged-in users.

> "All an attacker needs to get your key is their web browser."

They find something like

<script>
var mailchimpSecurity = {
    "api_key":"YOUR_REAL_MAILCHIMP_API_KEY",
    "other_var":"..."
};
</script>

Exploit Walkthrough

Let’s see a simulated example. Suppose your page at /newsletter has the MailChimp widget.

Steps

1. Browse to /newsletter

Code Snippet Example

<script>
window.mailchimp_data = {
    "api_key":"c3efxxxxxxxxxx-us1",
    "list_id":"d4eesxxxxxxx",
    "ajax_url":"https://example.com/wp-admin/admin-ajax.php";
};
</script>

With your MailChimp API key, attackers can

- Export your contacts/subscribers list
- Import/modify subscriber data (spamming, deleting, mass-subscribe/unsubscribe)

Damage your email reputation

> NOTE: MailChimp API keys are powerful—they allow *full programmatic control* of your MailChimp account!

Official Advisory & References

- Wordfence Advisory: Unauthenticated API Key Disclosure in Royal Elementor Addons
- NVD CVE-2023-3709
- WPScan Vulnerability Report

1. Update Immediately!

Upgrade Royal Elementor Addons to the latest stable version.

2. Reset All Exposed API Keys

Even after upgrading, you must reset your MailChimp API key if you used the MailChimp block. Here’s how:

- How to Reset Your MailChimp API Key
- Login to MailChimp, navigate to *Profile > Extras > API keys*, and revoke the compromised key. Generate a new one.

3. Monitor Activity

Review your MailChimp account for unusual activities—look for unknown campaigns and exported lists.

[x] Update Royal Elementor Addons plugin

- [x] Remove/recreate all MailChimp API keys used in the block

Conclusion

The CVE-2023-3709 vulnerability in Royal Elementor Addons could put your mailing lists and brand at risk if not addressed. Because attackers need only basic browser skills, it’s crucial to patch and rotate your API keys as soon as possible.

Always keep plugins up to date and never reuse API keys if they could have been exposed!

For more exclusive coverage on WordPress vulnerabilities and actionable tips, stay tuned!

References

- Wordfence Advisory
- Official Plugin Page
- MailChimp API Key Management

Timeline

Published on: 07/18/2023 03:15:00 UTC
Last modified on: 07/27/2023 15:04:00 UTC