12.2. 特定软件

12.2.1. proftpd is vulnerable to a Denial of Service attack.

Add DenyFilter \*.*/ to your configuration file, and for more information see http://www.proftpd.org/bugs.html.

12.2.2. After installing portsentry, there are a lot of ports open.

这是 portsentry 的工作方式. 它打开大约二十个未使用的端口用于确定端口扫描.