Unauthenticated Broken Access Control in WP User Manager <= 2.9.19 versions.

The WP User Manager plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the Connect::complete() function in versions up to, and including, 2.9.18. The function is registered on the admininit hook (which fires for every authenticated user that reaches /wp-admin/, including Subscribers) and performs no currentusercan() or nonce verification before fetching Stripe credentials from the external WPUM connect service and writing them (publishable key, secret key, gateway mode, and connected Stripe account ID) into the wpumsettings option via wpumupdateoption()/updateoption(). This makes it possible for authenticated attackers, with Subscriber-level access and above, to hijack the site's Stripe integration by completing their own Stripe Connect OAuth flow and then invoking the callback on the target site, causing all subsequent Stripe payments to be routed to the attacker's Stripe account.