请教一个问题，怎么解决？

说明: Some distributions of Apache, especially in Red Hat 7.0, allow an attacker to probe a system for user names via requests for user home pages (e.g., http://host/~username).  
修复: Disabling the UserDir directive in the Apache configuration file (httpd.conf) will prevent this, although it will also prevent users from providing their own web pages. Alternately, specify the same ErrorDocuments for both 403 (Forbidden) and 404 (Page Not Found) responses.  
这个要怎么做？