The midi-Synth plugin for WordPress is susceptible to arbitrary file uploads because of a lack of validation for file types and extensions within the 'export' AJAX action. This allows unauthenticated attackers to upload files to the affected server. Successful exploitation, which requires obtaining a valid nonce, could potentially lead to remote code execution. The nonce is exposed in frontend JavaScript, making it easily accessible to attackers.
**API Endpoint:** '/export'
**Vulnerable Parameter:** No specific parameters are mentioned, but the issue relates to file uploads handled by the 'export' AJAX action.
**Vulnerable Function:** The 'export' AJAX action is vulnerable.