The Points and Rewards for WooCommerce WordPress plugin before 2.10.1 does not have authorisation checks in place on a wallet and points update action that is available to unauthenticated users, and does not verify that the requester owns the account being changed, allowing unauthenticated attackers to arbitrarily modify or corrupt (including driving it negative) the stored wallet balance and loyalty points of any user. Modifying the wallet balance additionally requires the companion Wallet System for WooCommerce Points and Rewards for WooCommerce WordPress plugin before 2.10.1 to be active.