ZEND_API int zend_eval_string_ex(char *str, zval *retval_ptr, char *string_name, int handle_exceptions) /* {{{ */
{
	return zend_eval_stringl_ex(str, strlen(str), retval_ptr, string_name, handle_exceptions);
}
/* }}} */

The product uses a function that accepts a format string as an argument, but the format string originates from an external source.