Customer Reviews for WooCommerce < 5.104.0 - Unauthenticated Authentication Bypass to Arbitrary Review Submission via 'key' Parameter

Description

The Customer Reviews for WooCommerce plugin for WordPress is vulnerable to authentication bypass in all versions up to, and including, 5.103.0. This is due to the `create_review_permissions_check()` function comparing the user-supplied `key` parameter against the order's `ivole_secret_key` meta value using strict equality (`===`), without verifying that the stored key is non-empty. For orders where no review reminder email has been sent, the `ivole_secret_key` meta is not set, causing `get_meta()` to return an empty string. An attacker can supply `key: ""` to match this empty value and bypass the permission check. This makes it possible for unauthenticated attackers to submit, modify, and inject product reviews on any product — including products not associated with the referenced order — via the REST API endpoint `POST /ivole/v1/review`. Reviews are auto-approved by default since `ivole_enable_moderation` defaults to `"no"`.