The Paid Membership Subscriptions WordPress plugin before 3.0.9 does not verify that the amount and currency reported by the payment provider match the pending payment before completing it, allowing unauthenticated users to obtain a paid membership by paying an arbitrary lower amount.

The Paid Membership Subscriptions WordPress plugin before 3.0.9 does not verify that the amount and currency reported by the payment provider match the pending payment before completing it, allowing unauthenticated users to obtain a paid membership by paying an arbitrary lower amount.