MythicalDash: Unauthenticated payment bypass in Stripe success-redirect endpoint allows arbitrary free credit top-up

Summary

MythicalDash is a Pterodactyl client area. In 3.5.4-aurora and earlier, GET /api/stripe/process in backend/app/Api/System/Gateways/Stripe.php creates a pending row in mythicaldash_stripe_payments before Stripe checkout succeeds and embeds the payment code in the success redirect, while GET /api/stripe/processed accepts that code without constructing a Session, checking ownership, or retrieving the Stripe Checkout Session to require payment_status to be paid and amount_total to match the expected charge. An ordinary authenticated user can request an attacker-selected coins amount, abandon or fail payment, and submit the pending code directly to the unauthenticated processed endpoint. StripeDB::isPending() then permits User::addCreditsAtomic() to grant the unpaid amount and mark the row processed even though Stripe has not confirmed payment. This permits arbitrary free virtual-currency top-ups and direct financial loss through consumption of hosting resources. No fixed version is available as of this review.