CVE-2023-5419 - Funnelforms Free WordPress Plugin Vulnerability: Unauthorized Data Modification and Test Email Exploitation

In today's digital landscape, securing web applications is essential to protect sensitive data from unauthorized access. As many WordPress users rely on plugins to enhance their website's functionality, it is crucial to show due diligence in patching and updating these tools to resist potential cyber threats. Here, we will discuss an ongoing issue (CVE-2023-5419) with the Funnelforms Free WordPress plugin that grants authenticated attackers unauthorized access to modify data and exploit test email functionalities.

Problem

The Funnelforms Free plugin for WordPress (Version 3.4 and below) is vulnerable to unauthorized modification of data due to a missing capability check on the fnsf_af2_test_mail function. This capability check ensures that only users with specific permissions (such as admin-level ones) have the ability to perform particular operations.

Due to the absence of this security measure, any authenticated attacker (including those with subscriber-level permissions) can potentially send test emails to arbitrary email addresses. This vulnerability poses a risk of exploitation by ill-intentioned agents who might misuse the plugin's test email feature to execute phishing attacks or distribute spam emails.

Exploit Details

The vulnerability resides in the fnsf_af2_test_mail function, which lacks a security check before allowing the user to send test emails using the website's mailing functionality. Here is the code snippet for the function:

function fnsf_af2_test_mail() {
    $test_mail_to      = $_POST['test_mail_to'];
    $test_mail_subject = $_POST['test_mail_subject'];
    $test_mail_body    = $_POST['test_mail_body'];

    if (wp_mail($test_mail_to, $test_mail_subject, $test_mail_body)) {
        echo "The test email was sent successfully!";
    } else {
        echo "An error occurred while sending the test email.";
    }

    wp_die();
}
add_action('wp_ajax_fnsf_af2_test_mail', 'fnsf_af2_test_mail');

To mitigate this vulnerability, a proper capability check must be in place before allowing users to send test emails. The check should ensure that only authorized users with specific permissions, such as admins, can perform this operation. A possible solution could look like this:

function fnsf_af2_test_mail() {
    // Add capability check
    if (!current_user_can('manage_options')) {
        wp_die('You do not have the required permissions to perform this action.');
    }

    $test_mail_to      = $_POST['test_mail_to'];
    $test_mail_subject = $_POST['test_mail_subject'];
    $test_mail_body    = $_POST['test_mail_body'];

    if (wp_mail($test_mail_to, $test_mail_subject, $test_mail_body)) {
        echo "The test email was sent successfully!";
    } else {
        echo "An error occurred while sending the test email.";
    }

    wp_die();
}
add_action('wp_ajax_fnsf_af2_test_mail', 'fnsf_af2_test_mail');

Original References

1. Official WordPress Plugin Repository: Funnelforms Free
2. WordPress Plugin Vulnerability Database: CVE-2023-5419
3. The official Common Vulnerabilities and Exposures (CVE) database: CVE-2023-5419

Conclusion

Maintaining the security of your WordPress website is vital to prevent unauthorized access and exploitation of vulnerabilities by cybercriminals. Identifying and addressing issues like CVE-2023-5419, present in the Funnelforms Free plugin, is critical to ensuring the integrity of your platform.

By implementing proper capability checks and updating plugins to their newest versions, users can effectively reduce their risk of exposure to such vulnerabilities. Keep a vigilant eye on your website's security by educating yourself and staying informed about potential threats that might affect your WordPress site.

Timeline

Published on: 11/22/2023 16:15:12 UTC
Last modified on: 11/27/2023 20:16:37 UTC