Otter Blocks <= 3.1.4 - Improper Authorization to Unauthenticated Purchase Verification Bypass via Forged Cookie

The Otter Blocks plugin for WordPress is vulnerable to Purchase Verification Bypass in all versions up to, and including, 3.1.4. This is due to the 'get_customer_data' method relying on an unsigned 'o_stripe_data' cookie to determine Stripe product ownership for unauthenticated users. The 'check_purchase' method trusts this cookie data without performing server-side verification against the Stripe API for one-time 'payment' mode purchases. This makes it possible for unauthenticated attackers to bypass Stripe purchase-gated content visibility conditions by forging the 'o_stripe_data' cookie with a target product ID, which is publicly exposed in the checkout block's HTML source.