[root@deep]# chmod 600 /etc/inetd.conf
第二步:确信文件的所有者是root。
[root@deep]# stat /etc/inetd.conf
第三步:编辑“inetd.conf”文件(vi /etc/inetd.conf),禁止所有不需要的服务,如:ftp、 telnet、 shell、 login、 exec、talk、ntalk、 imap、 pop-2、pop-3、finger、auth,等等。如果你觉得某些服务有用,可以不禁止这些服务。但是,把这些服务禁止掉,系统受攻击的可能性就会小很多。改变后的“inetd.conf”文件的内容如下面所示:
# To re-read this file after changes, just do a 'killall -HUP inetd'
#
#echo stream tcp nowait root internal
#echo dgram udp wait root internal
#discard stream tcp nowait root internal
#discard dgram udp wait root internal
#daytime stream tcp nowait root internal
#daytime dgram udp wait root internal
#chargen stream tcp nowait root internal
#chargen dgram udp wait root internal
#time stream tcp nowait root internal
#time dgram udp wait root internal
#
# These are standard services.
#
#ftp stream tcp nowait root /usr/sbin/tcpd in.ftpd -l -a
#telnet stream tcp nowait root /usr/sbin/tcpd in.telnetd
#
# Shell, login, exec, comsat and talk are BSD protocols.
#
#shell stream tcp nowait root /usr/sbin/tcpd in.rshd
#login stream tcp nowait root /usr/sbin/tcpd in.rlogind
#exec stream tcp nowait root /usr/sbin/tcpd in.rexecd
#comsat dgram udp wait root /usr/sbin/tcpd in.comsat
#talk dgram udp wait root /usr/sbin/tcpd in.talkd
#ntalk dgram udp wait root /usr/sbin/tcpd in.ntalkd
#dtalk stream tcp wait nobody /usr/sbin/tcpd in.dtalkd
#
# Pop and imap mail services et al
#
#pop-2 stream tcp nowait root /usr/sbin/tcpd ipop2d
#pop-3 stream tcp nowait root /usr/sbin/tcpd ipop3d
#imap stream tcp nowait root /usr/sbin/tcpd imapd
#
# The Internet UUCP service.
#
#uucp stream tcp nowait uucp /usr/sbin/tcpd /usr/lib/uucp/uucico -l
#
# Tftp service is provided primarily for booting. Most sites
# run this only on machines acting as "boot servers." Do not uncomment
# this unless you *need* it.
#
#tftp dgram udp wait root /usr/sbin/tcpd in.tftpd
#bootps dgram udp wait root /usr/sbin/tcpd bootpd
#
# Finger, systat and netstat give out user information which may be
# valuable to potential "system crackers." Many sites choose to disable
# some or all of these services to improve security.
#
#finger stream tcp nowait root /usr/sbin/tcpd in.fingerd
#cfinger stream tcp nowait root /usr/sbin/tcpd in.cfingerd
#systat stream tcp nowait guest /usr/sbin/tcpd /bin/ps -auwwx
#netstat stream tcp nowait guest /usr/sbin/tcpd /bin/netstat -f inet
#
# Authentication
#