EspoCRM is an open source customer relationship management application. Prior to version 9.3.4, EspoCRM's built-in formula scripting engine allowing updating attachment's sourceId thus allowing an authenticated admin to overwrite the "sourceId" field on "Attachment" entities. Because "sourceId" is concatenated directly into a file path with no sanitization in "EspoUploadDir::getFilePath()", an attacker can redirect any file read or write operation to an arbitrary path within the web server's "open_basedir" scope. Version 9.3.4 fixes the issue.