WWBN AVideo is an open source video platform. In versions up to and including 29.0, plugin/PayPalYPT/agreementCancel.json.php cancels a PayPal billing agreement using an attacker-supplied agreement parameter without verifying that the authenticated user owns the agreement. A low-privilege authenticated user who learns or obtains another user's PayPal billing agreement ID can silently suspend the victim's recurring subscription, causing revenue loss to the platform and loss of paid service to the victim. Commit 0da3dcff1eda2f497694bf82b559829471c292c2 contains an updated fix.