19. 重新設置/etc/rc.d/init.d/目錄下所有文件的許可權限
root@deep]# chmod -R 700 /etc/rc.d/init.d/*
僅僅root可以讀，寫，執行上述所有script file.
20. The /etc/rc.d/rc.local ile
默認地，當你login到linux server時，它告訴你linux版本名，內核版本名和服務器
主機名。它給了你太多的信息，如果你就希望得到提示login: ,編輯/etc/rc.d/rc.local放#在下面的行前面：
# This will overwrite /etc/issue at every boot. So, make any changes you
# want to make to /etc/issue here or you will lose them when you reboot.
#echo "" >; /etc/issue
#echo "$R" >;>; /etc/issue
#echo "Kernel $(uname -r) on $a $(uname -m)" >;>; /etc/issue
#
#cp -f /etc/issue /etc/issue.net
#echo >;>; /etc/issue
然後，做下面的事情:
root@deep]# rm -f /etc/issue
root@deep]# rm -f /etc/issue.net
root@deep]# touch /etc/issue
root@deep]# touch /etc/issue.net
21. 被root擁有的程序的位。
移走那些被root擁有程序的s位標志，當然有些程序需要這個，用命令‘chmod a-s’完成這個。
注：前面帶（*）號的那些程序一般不需要擁有s位標志。
root@deep]# find / -type f \( -perm -04000 -o -perm -02000 \) \-exec ls –lg {} \;
-rwsr-xr-x 1 root root 33120 Mar 21 1999 /usr/bin/at
*-rwsr-xr-x 1 root root 30560 Apr 15 20:03 /usr/bin/cage
*-rwsr-xr-x 1 root root 29492 Apr 15 20:03 /usr/bin/gpasswd
-rwsr-xr-x 1 root root 3208 Mar 22 1999 /usr/bin/disable-paste
-rwxr-sr-x 1 root man 32320 Apr 9 1999 /usr/bin/man
-r-s--x--x 1 root root 10704 Apr 14 17:21 /usr/bin/passwd
-rws--x--x 2 root root 517916 Apr 6 1999 /usr/bin/suidperl
-rws--x--x 2 root root 517916 Apr 6 1999 /usr/bin/sperl5.00503
-rwxr-sr-x 1 root mail 11432 Apr 6 1999 /usr/bin/lockile
-rwsr-sr-x 1 root mail 64468 Apr 6 1999 /usr/bin/procmail
-rwsr-xr-x 1 root root 21848 Aug 27 11:06 /usr/bin/crontab
-rwxr-sr-x 1 root slocate 15032 Apr 19 14:55 /usr/bin/slocate
*-r-xr-sr-x 1 root tty 6212 Apr 17 11:29 /usr/bin/wall
*-rws--x--x 1 root root 14088 Apr 17 12:57 /usr/bin/cfn
*-rws--x--x 1 root root 13800 Apr 17 12:57 /usr/bin/cs *-rws--x--x 1 root root 5576 Apr 17 12:57 /usr/bin/newgrp
*-rwxr-sr-x 1 root tty 8392 Apr 17 12:57 /usr/bin/write
-rwsr-x--- 1 root squid 14076 Oct 7 14:48 /usr/lib/squid/pinger
-rwxr-sr-x 1 root utmp 15587 Jun 9 09:30 /usr/sbin/utempter
*-rwsr-xr-x 1 root root 5736 Apr 19 15:39 /usr/sbin/usernetctl
*-rwsr-xr-x 1 root bin 16488 Jul 6 09:35 /usr/sbin/traceroute
-rwsr-sr-x 1 root root 299364 Apr 19 16:38 /usr/sbin/sendmail
-rwsr-xr-x 1 root root 34131 Apr 16 18:49 /usr/libexec/pt_cown
-rwsr-xr-x 1 root root 13208 Apr 13 14:58 /bin/su
*-rwsr-xr-x 1 root root 52788 Apr 17 15:16 /bin/mount
*-rwsr-xr-x 1 root root 26508 Apr 17 20:26 /bin/umount
*-rwsr-xr-x 1 root root 17652 Jul 6 09:33 /bin/ping
-rwsr-xr-x 1 root root 20164 Apr 17 12:57 /bin/login
*-rwxr-sr-x 1 root root 3860 Apr 19 15:39 /sbin/netreport
-r-sr-xr-x 1 root root 46472 Apr 17 16:26 /sbin/pwdb_ckpwd
root@deep]# chmod a-s /usr/bin/cage
root@deep]# chmod a-s /usr/bin/gpasswd
root@deep]# chmod a-s /usr/bin/wall
root@deep]# chmod a-s /usr/bin/cfn
root@deep]# chmod a-s /usr/bin/cs root@deep]# chmod a-s /usr/bin/newgrp
root@deep]# chmod a-s /usr/bin/write
root@deep]# chmod a-s /usr/sbin/usernetctl
root@deep]# chmod a-s /usr/sbin/traceroute
root@deep]# chmod a-s /bin/mount
root@deep]# chmod a-s /bin/umount
root@deep]# chmod a-s /bin/ping
root@deep]# chmod a-s /sbin/netreport
你可以用下面的命令查找所有帶s位標志的程序：
root@deep]# find / -type f \( -perm -04000 -o -perm -02000 \) \-exec ls -lg {} \;
>; suid-sgid-results
把結果輸出到文件suid-sgid-results中。
為了查找所有可寫的文件和目錄，用下面的命令：
root@deep]# find / -type f \( -perm -2 -o -perm -20 \) -exec ls -lg {} \; >; ww-files-results
root@deep]# find / -type d \( -perm -2 -o -perm -20 \) -exec ls -ldg {} \; >; ww-directories-results
用下面的命令查找沒有擁有者的文件：
root@deep]# find / -nouser -o -nogroup >; unowed-results
用下面的命令查找所有的.rhosts文件：
root@deep]# find /home -name .rhosts >; rhost-results
