Easy Digital Download < 3.5.3 - Insufficient Verification to Order Manipulation

Description

The plugin is vulnerable to Order Manipulation due to an order verification bypass. The verification is unconditionally skipped when the POST body includes verification_override=1. Because this value is attacker-supplied, an unauthenticated actor can submit a forged IPN and have it treated as verified, even on production sites and with verification otherwise enabled. A valid PayPal transaction id is needed, restricting order manipulation to orders placed by the attacker. This, in turn, requires them to have a customer account.