The CalJ plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 1.5. This is due to a missing capability check in the CalJSettingsPage class constructor, which processes the 'save-obtained-key' operation directly from POST data without verifying that the requesting user has the 'manage_options' capability, and without any nonce verification. The plugin bootstrap file (calj.php) instantiates CalJSettingsPage whenever is_admin() returns true, which is the case for any authenticated user making requests to wp-admin URLs (including admin-ajax.php). This makes it possible for authenticated attackers, with Subscriber-level access and above, to modify the plugin's API key setting and clear the Shabbat cache, effectively taking control of the plugin's API integration.