Pie Register Premium WordPress Plugin Unrestricted File Upload Vulnerability

The Pie Register Premium plugin for WordPress is vulnerable to an unrestricted file type upload flaw in all versions up to and including 3.8.4.0. The issue exists in the piereg_file_upload function.

The plugin performs file type validation using wp_check_filetype and wp_check_filetype_and_ext, but it never checks whether those validation calls produced errors before move_uploaded_file() is called. The AJAX handler also lacks nonce or capability checks.

• Affected versions: all versions up to and including 3.8.4.0
• Attackers: unauthenticated
• Impact: upload of dangerous file types such as PHP scripts, potentially leading to remote code execution
• The server returns the generated destination filename, giving the attacker the exact path needed to trigger the uploaded file