centos7离线升级openssh,漏洞修复

Posted 2023-05-03

参考技术A yum -y install xinetd telnet-server

配置/etc/xinetd.d/telnet

cat > /etc/xinetd.d/telnet <<eof p=""> </eof>

service telnet



disable = yes

flags = REUSE

socket_type = stream

wait = no

user = root

server = /usr/sbin/in.telnetd

log_on_failure += USERID



EOF

配置telnet登录的终端类型

cat >> /etc/securetty <<eof p=""> </eof>

pts/0

pts/1

pts/2

pts/3

EOF

启动telnet

systemctl enable xinetd --now

systemctl enable telnet.socket --now

wget http://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-8.8p1.tar.gz

wget https://www.openssl.org/source/openssl-1.1.1j.tar.gz --no-check-certificate

wget http://www.zlib.net/zlib-1.2.12.tar.gz

tar -zxvf zlib-1.2.12.tar.gz

cd zlib-1.2.12

./configure --prefix=/usr/local/zlib

make && make install

tar -zxvf openssl-1.1.1j.tar.gz

cd openssl-1.1.1j

./config --prefix=/usr/local/ssl -d shared

make && make install

echo '/usr/local/ssl/lib' >> /etc/ld.so.conf

ldconfig -v

openssl version -a

tar -zxvf openssh-8.8p1.tar.gz

cd openssh-8.8p1

./configure --prefix=/usr/local/openssh --with-zlib=/usr/local/zlib --with-ssl-dir=/usr/local/ssl

make && make install

配置文件备份和修改

#sshd_config文件修改

echo 'PermitRootLogin yes' >>/usr/local/openssh/etc/sshd_config

echo 'PubkeyAuthentication yes' >>/usr/local/openssh/etc/sshd_config

echo 'PasswordAuthentication yes' >>/usr/local/openssh/etc/sshd_config

# 备份原有文件，并将新的配置复制到指定目录

mv /etc/ssh/sshd_config /etc/ssh/sshd_config.bak

cp /usr/local/openssh/etc/sshd_config /etc/ssh/sshd_config

mv /usr/sbin/sshd /usr/sbin/sshd.bak

cp /usr/local/openssh/sbin/sshd /usr/sbin/sshd

mv /usr/bin/ssh /usr/bin/ssh.bak

cp /usr/local/openssh/bin/ssh /usr/bin/ssh

mv /usr/bin/ssh-keygen /usr/bin/ssh-keygen.bak

cp /usr/local/openssh/bin/ssh-keygen /usr/bin/ssh-keygen

mv /etc/ssh/ssh_host_ecdsa_key.pub /etc/ssh/ssh_host_ecdsa_key.pub.bak

cp /usr/local/openssh/etc/ssh_host_ecdsa_key.pub /etc/ssh/ssh_host_ecdsa_key.pub

# 修改systemd参数（去掉Type或改为Type=simple）

vim /usr/lib/systemd/system/sshd.service

[Unit]

Description=OpenSSH server daemon

Documentation=man:sshd(8) man:sshd_config(5)

After=network.target sshd-keygen.service

Wants=sshd-keygen.service

[Service]

#Type=notify

Type=simple

EnvironmentFile=/etc/sysconfig/sshd

ExecStart=/usr/sbin/sshd -D $OPTIONS

ExecReload=/bin/kill -HUP $MAINPID

KillMode=process

Restart=on-failure

RestartSec=42s

[Install]

WantedBy=multi-user.target

重启sshd服务

systemctl daemon-reload

systemctl restart sshd

systemctl status sshd

# 验证是否升级成功

ssh -V

OpenSSH漏洞修复——Ubuntu系统

漏洞名称：OpenSSH漏洞

风险描述：OpenSSH 是一组用于安全地访问远程计算机的连接工具,低版本爆出的高危漏洞太多

修复建议：升级到最新版本

 OpenSSH 升级加固实例

(一)   升级条件准备

²  关闭防火墙

# ufw disable

²  安装与启用telnet

开启telnet server，以防止升级OpenSSH时导致远程连接异常，具体Telnet服务安装与开启命令操作如下。

# apt-get install -y openbsd-inetd

# apt-get install -y telnetd

# service openbsd-inetd start

²  下载相关升级包

# wget https://cloudflare.cdn.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-7.4p1.tar.gz --no-check-certificate

# wget http://www.zlib.net/zlib-1.2.11.tar.gz

# wget https://www.openssl.org/source/openssl-1.0.2k.tar.gz

²  安装zlib依赖库

# tar zxvf zlib-1.2.11.tar.gz

# cd zlib-1.2.11

# ./configure

# make && make install

# echo "/usr/local/lib" >> /etc/ld.so.conf

# ldconfig

²  添加普通账户

# useradd iflytek

# passwd iflytek

(二)   OpenSSL升级

# tar zxvf openssl-1.0.2k.tar.gz

# cd openssl-1.0.2k

# ./config shared -fPIC

# make && make install

# echo "/usr/local/ssl/lib " >> /etc/ld.so.conf

# ldconfig

# rm -rf /usr/bin/openssl

# ln -s /usr/local/ssl/bin/openssl /usr/bin/openssl

# openssl version

 

(三)   OpenSSH升级

使用命令“telnet IP”远程连接服务器，关闭SSH服务以便升级。

# 停止sshd服务

# service sshd stop

# apt安装libpam0g-dev

# apt-get install libpam0g-dev # 缺少libpam0g-dev会报错

# 删除原ssh中的相关配置文件

# rm -rf /etc/ssh /usr/bin/scp /usr/bin/sftp /usr/bin/ssh* /usr/sbin/sshd

# rm -rf /lib/x86_64-linux-gnu/libssl.so.1.0.0

# rm -rf /lib/x86_64-linux-gnu/libcrypto.so.1.0.0

# cp /usr/local/ssl/lib/libssl.so.1.0.0 /lib/x86_64-linux-gnu/

# cp /usr/local/ssl/lib/libcrypto.so.1.0.0 /lib/x86_64-linux-gnu/

# 解压新版openssh并编译安装

# tar zxvf openssh-7.4p1.tar.gz

# cd openssh-7.4p1

# ./configure --prefix=/usr/local/ssh --sysconfdir=/etc/ssh --with-md5-passwords --with-pam --with-ssl-dir=/usr/local/ssl  --mandir=/usr/share/man --with-zlib=/usr/local/lib --with-privsep-path=/var/empty --with-privsep-user=sshd --with-ssl-engine

# make && make install

 

 

 如果遇到这个错误，说明pam没装，需要装下：apt-get install pam

 

# 创建新版ssh服务的相关软链接

# ln -s /usr/local/ssh/bin/ssh /usr/bin/ssh

# ln -s /usr/local/ssh/bin/scp /usr/bin/scp

# ln -s /usr/local/ssh/bin/sftp /usr/bin/sftp

# ln -s /usr/local/ssh/bin/ssh-add /usr/bin/ssh-add

# ln -s /usr/local/ssh/bin/ssh-agent /usr/bin/ssh-agent

# ln -s /usr/local/ssh/bin/ssh-keygen /usr/bin/ssh-keygen

# ln -s /usr/local/ssh/bin/ssh-keyscan /usr/bin/ssh-keyscan

# ln -s /usr/local/ssh/sbin/sshd /usr/sbin/sshd

#配置允许root远程使用ssh登录（建议使用普通账号作为远程运维登录使用，不要开启root远程登录）

# vi /etc/ssh/sshd_config

去除“#PermitRootLogin prohibit-password”中注释，并修改“prohibit-password”为“yes”，最后保存退出；

# service sshd start

如果出错按照提示操作

 

# ssh -V