由于之前的项目用的ssh的版本较低，最近被频繁查出有安全漏洞
不得不进行升级避免安全问题
操作步骤
一、开启telnet
记得先测试telnet能否成功登录再升级openssh不然ssh会挂掉，当然如果你是在本机升级可以省略这一步 yum install telnet-server telnet systemctl start telnet.socket systemctl enable telnet.socket lsof -i:23 #开放防火墙策略 firewall-cmd --zone=public --add-port=23/tcp --permanent
二、备份旧的ssh
#查询ssh目录 whereis sshd mv /usr/sbin/sshd /usr/sbin/sshd.bak whereis ssh mv /usr/bin/ssh /usr/bin/ssh.bak whereis ssh-keygen mv /usr/bin/ssh-keygen /usr/bin/ssh-keygen.bak
三、卸载旧的openssh-server
yum remove openssh-server
四、安装新的openssh-server
# 安装依赖
yum install zlib-devel openssl-devel -y
cd /usr/local wget https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-8.8p1.tar.gz tar -zxvf openssh-8.8p1.tar.gz cd openssh-8.8p1 ./configure make & make install # 设置全局使用 cp /usr/local/sbin/sshd /usr/sbin cp /usr/local/bin/ssh /usr/bin cp /usr/local/bin/ssh-keygen /usr/bin/
五、查看新本版
ssh -V
六、启动ssh 并设置开机自启
cp /usr/local/openssh-8.8p1/contrib/redhat/sshd.init /etc/init.d/sshd /etc/init.d/sshd restart systemctl status sshd systemctl enable sshd
七、安装后可能会导致ssh无法连接，解决办法如下
第一步： cp /usr/local/openssh-8.8p1/sshd_config /etc/ssh/ 第二步： vim /etc/ssh/sshd_config 找到PermitRootLogin without-password 改成PermitRootLogin yes 第三步： vim /etc/init.d/sshd 在48行下面加上 OPTIONS="-f /etc/ssh/sshd_config"
第四步： systemctl daemon-reload systemctl restart sshd
如果报如下异常：
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ECDSA key sent by the remote host is
SHA256:9XvufSSIeZ7MAurIZ1Qw9Z13YV1Zcim2kthmAlECgYw.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /root/.ssh/known_hosts:8
ECDSA host key for 192.168.122.100 has changed and you have requested strict checking.
Host key verification failed.
lost connection
尝试删除 rm -rf ~/.ssh/known_hosts
还有本地的：~/.ssh/known_hosts