ExactMetrics 7.1.0 - 9.0.2 - Improper Privilege Management to Role Privilege Escalation via Settings Update

Description

The plugin is vulnerable to Improper Privilege Management due to the `update_settings()` function accepting arbitrary plugin setting names without a whitelist of allowed settings. This makes it possible for authenticated attackers with the `exactmetrics_save_settings` capability to modify any plugin setting, including the `save_settings` option that controls which user roles have access to plugin functionality. The admin intended to delegate configuration access to a trusted user, not enable that user to delegate access to everyone. By setting `save_settings` to include `subscriber`, an attacker can grant plugin administrative access to all subscribers on the site.