Simple Fields 0.2 through 0.3.5 WordPress Plugin contains a local file inclusion vulnerability that allows unauthenticated attackers to read arbitrary files by injecting null bytes into the wp_abspath parameter on PHP versions before 5.3.4. Attackers can supply malicious wp_abspath values to simple_fields.php to include files like /etc/passwd or inject PHP code into Apache logs for remote code execution when allow_url_include is enabled.