OpenEMR before 8.5.0 RCE via Stored ERA Upload and Background Services

OpenEMR before 8.5.0 contains a remote code execution vulnerability that allows authenticated billing users to store attacker-controlled PHP by uploading a malformed ERA file to era_payments.php. Attackers with a database-write primitive such as SQL injection can register a background_services row whose require_once loads the stored .edi file, executing PHP as the web-server user.