The payever – WooCommerce Gateway plugin for WordPress is vulnerable to arbitrary file upload leading to remote code execution in various versions up to, and including, 4.8.0. Three WooCommerce-API callbacks (payever_set_sandbox_api_keys, payever_toggle_subscription, payever_synchronization_incoming) are registered with no authentication, capability check, or nonce, and the upload_image() routine writes a remotely fetched file to the public uploads directory using an attacker-controlled basename() BEFORE validating the file type. This makes it possible for unauthenticated attackers to write an executable PHP file and achieve remote code execution. NOTE: the token-recovery leg of the full chain depends on the plugin's outbound validateToken() call to Payever's service; the unauthenticated hard-coded-credential identity overwrite (CWE-862/CWE-798) is independently exploitable.