centos 系统加固脚本

运行
curl -L https://github.com/mufengcoding/shell/releases/download/1.1/security.sh | bash
注意只运行一次 ，多次运行可能会 gg
github 地址：https://github.com/mufengcoding/shell/blob/master/security.sh

  

#!/bin/sh
# desc: setup linux system security
# author:mufengs
# powered by blog.mufengs.com
# version 0.1.2 written by 2018.11.24
#account setup
  

#锁定以下用户

passwd -l xfs

passwd -l news

passwd -l nscd

passwd -l dbus

passwd -l vcsa

passwd -l games

passwd -l nobody

passwd -l avahi

passwd -l haldaemon

passwd -l gopher

passwd -l ftp

passwd -l mailnull

passwd -l pcap

passwd -l mail

passwd -l shutdown

passwd -l halt

passwd -l uucp

passwd -l operator

passwd -l sync

passwd -l adm

passwd -l lp

  

#将帐号相关文件设为只读属性

\# chattr /etc/passwd /etc/shadow

chattr +i /etc/passwd

chattr +i /etc/shadow

chattr +i /etc/group

chattr +i /etc/gshadow

  

#系统登陆失败3次锁定5分钟

\# add continue input failure 3 ,passwd unlock time 5 minite

sed -i 's#auth required pam\_env.so#auth required pam\_env.so \\n auth required pam\_tally.so onerr=fail deny=3 unlock\_time=300 \\n auth required /lib/security/$ISA/pam\_tally.so onerr=fail deny=3 unlock\_time=300#' /etc/pam.d/system-auth

  

#5分钟超时登出

\# system timeout 5 minite auto logout

echo  "TMOUT=300"  \>>/etc/profile

  

#设置历史命令为10条

\# will system save history command list to 10

sed -i "s/HISTSIZE=1000/HISTSIZE=10/" /etc/profile

  

#让以上配置生效

\# enable /etc/profile go!

source /etc/profile

  

#防范SYN Flood攻击

\# add syncookie enable /etc/sysctl.conf

echo  "net.ipv4.tcp\_syncookies=1"  \>> /etc/sysctl.conf

sysctl -p \# exec sysctl.conf enable

  
  

\# optimizer sshd\_config

  

sed -i "s/#MaxAuthTries 6/MaxAuthTries 6/" /etc/ssh/sshd\_config

sed -i "s/#UseDNS yes/UseDNS no/" /etc/ssh/sshd\_config

  

#限制重要命令的权限

\# limit chmod important commands

chmod 700 /bin/ping

chmod 700 /usr/bin/finger

chmod 700 /usr/bin/who

chmod 700 /usr/bin/w

chmod 700 /usr/bin/locate

chmod 700 /usr/bin/whereis

chmod 700 /sbin/ifconfig

chmod 700 /usr/bin/pico

chmod 700 /bin/vi

chmod 700 /usr/bin/which

chmod 700 /usr/bin/gcc

chmod 700 /usr/bin/make

chmod 700 /bin/rpm

  

\# history security

  

chattr +a /root/.bash\_history

chattr +i /root/.bash\_history

  

\# write important command md5

cat \> list << "EOF" &&

/bin/ping

/bin/finger

/usr/bin/who

/usr/bin/w

/usr/bin/locate

/usr/bin/whereis

/sbin/ifconfig

/bin/pico

/bin/vi

/usr/bin/vim

/usr/bin/which

/usr/bin/gcc

/usr/bin/make

/bin/rpm

/bin/ls

/bin/top

/bin/ps

EOF

  

for  i  in  \`cat list\`

do

if \[ !  \-x  $i \];then

echo  "$i not found,no md5sum!"

else

md5sum $i  \>> /var/log/\`hostname\`.log

fi

done

rm -f list

  

\# 修改默认umask

perl -npe 's/umask\\s+0\\d2/umask 077/g' -i /etc/bashrc

perl -npe 's/umask\\s+0\\d2/umask 077/g' -i /etc/csh.cshrc

  
  

#cron加固

echo  "Locking down Cron"

  

touch /etc/cron.allow

  

chmod 600 /etc/cron.allow

  

awk -F: '{print $1}' /etc/passwd | grep -v root \> /etc/cron.deny

  

echo  "Locking down AT"

  

touch /etc/at.allow

  

chmod 600 /etc/at.allow

  

awk -F: '{print $1}' /etc/passwd | grep -v root \> /etc/at.deny

  
  

#内核加固

cat <<  EOF >> /etc/sysctl.conf

net.ipv4.ip\_forward = 0

  

net.ipv4.conf.all.send\_redirects = 0

  

net.ipv4.conf.default.send\_redirects = 0

  

net.ipv4.tcp\_max\_syn\_backlog = 1280

  

net.ipv4.icmp\_echo\_ignore\_broadcasts = 1

  

net.ipv4.conf.all.accept\_source\_route = 0

  

net.ipv4.conf.all.accept\_redirects = 0

  

net.ipv4.conf.all.secure\_redirects = 0

  

net.ipv4.conf.all.log\_martians = 1

  

net.ipv4.conf.default.accept\_source\_route = 0

  

net.ipv4.conf.default.accept\_redirects = 0

  

net.ipv4.conf.default.secure\_redirects = 0

  

net.ipv4.icmp\_echo\_ignore\_broadcasts = 1

  

net.ipv4.icmp\_ignore\_bogus\_error\_responses = 1

  

net.ipv4.tcp\_syncookies = 1

  

net.ipv4.conf.all.rp\_filter = 1

  

net.ipv4.conf.default.rp\_filter = 1

  

net.ipv4.tcp\_timestamps = 0

EOF

  

\# 禁止所有TCP Wrappers

echo  "ALL:ALL"  \>> /etc/hosts.deny

echo  "sshd:ALL"  \>> /etc/hosts.allow

  
  

#防止缓冲区溢出

sysctl -w kernel.exec-shield=1

sysctl -q -n -w kernel.randomize\_va\_space=2

echo  "kernel.exec-shield = 1"\>>/etc/sysctl.conf

echo  "kernel.randomize\_va\_space = 2"\>>/etc/sysctl.conf

  

#禁止空密码登陆

sed -i 's/\\<nullok\\>//g' /etc/pam.d/system-auth

  

#定时更新

yum -y install yum-cron

chkconfig yum-cron on