As detailed in a separate post, we took a look at the WordPress plugin WooCommerce Fraud Prevention Plugin after seeing it mentioned in a news story. We found it is insecure and that the security leads to at least one vulnerability, as anyone logged in to WordPress can reset the plugins settings.

The plugin registers the function wcblu_reset_settings() to be accessible through WordPress’ AJAX functionality to anyone logged in to WordPress:

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$this->loader->add_action( 'wp_ajax_wcblu_reset_settings', $plugin_admin, 'wcblu_reset_settings' );

That function, which is located in the file /admin/class-woocommerce-blocker-prevent-fake-orders-and-blacklist-fraud-customers-admin.php, empties the plugin’s settings without doing any security checks first:

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public function wcblu_reset_settings()
{
	update_option( 'wcblu_option', '' );
	die;
}

There should be both a capabilities check to limit who has access to the functionality and a nonce check to prevent cross-site request forgery (CSRF).

WordPress Causes Full Disclosure

As a protest of the moderators of the WordPress Support Forum’s continued inappropriate behavior we changed from reasonably disclosing to full disclosing vulnerabilities for plugins in the WordPress Plugin Directory in protest, until WordPress gets that situation cleaned up, so we are releasing this post and then leaving a message about that for the developer through the WordPress Support Forum. (For plugins that are also in the ClassicPress Plugin Directory, we will follow our reasonable disclosure policy.)

You can notify the developer of this issue on the forum as well.

After four years, the moderators have finally tacitly admitted they were behaving inappropriately and have made moves to fix the problems (though incompletely), so these full disclosures can be ended if they simply restore access to our accounts and plugins in the Plugin Directory. Hopefully that takes less than four years.

Update: To clear up the confusion where developers claim we hadn’t tried to notify them through the Support Forum (while at the same time moderators are complaining about us doing just that), here is the message we left for this vulnerability:

Proof of Concept

The following proof of concept will reset the plugin’s settings, when logged in to WordPress.

Replace “[path to WordPress]” with the location of WordPress.

http://[path to WordPress]/wp-admin/admin-ajax.php?action=wcblu_reset_settings

Concerned About The Security of the Plugins You Use?

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