WWBN AVideo 29.0 through 29.4.0 contains a race condition vulnerability in plugin/PayPalYPT/ipn.php that allows attackers to bypass IPN replay protection due to a non-atomic deduplication check and insert. Attackers can concurrently replay a captured valid recurring-payment notification so both requests pass isRecurringPaymentIdUsed(), obtaining duplicate wallet credits and subscription renewals.
CWE-367