Rocky Linux 9系统 OpenSSH CVE-2024-6387 漏洞修复
- 1、漏洞修复
- 2、修复思路
- 3、修复方案
- 3.1、方案一
- 3.2、方案二
- 4、总结
- 5、参考
1、漏洞修复
CVE-2024-6387：regreSSHion：OpenSSH 服务器中的远程代码执行（RCE），至少在基于 glibc 的 Linux 系统上可被利用。
根据 oss-security - CVE-2024-6387: RCE in OpenSSH’s server, on glibc-based Linux systems 的发现并由 oss-security - Announce: OpenSSH 9.8 released 上游总结，在 Portable OpenSSH 版本 8.5p1 至 9.7p1（含）中，sshd(8) 存在一个严重漏洞，可能允许以 root 权限执行任意代码。
在 32 位的 Linux/glibc 系统上，成功利用该漏洞已被证明，且需要启用地址空间布局随机化（ASLR）。在实验室条件下，攻击平均需要 6-8 小时的持续连接，直到服务器达到最大连接数为止。目前尚未证明在 64 位系统上可以利用该漏洞，但认为这可能是可行的。这些攻击很有可能会得到进一步改进。
公开披露日期： 2024年7月1日
影响范围： Rocky Linux 9
**修复版本：**8.7p1-38.el9_4.security.0.5 2024 年 7 月 1 日可用。
不受影响： Rocky Linux 8
2、修复思路
安装 8.7p1-38.el9_4.security.0.5 即可。
3、修复方案
方案一采用在线方式修复，方案二采用离线方式修复。根据自身的网络环境采用对应的方式进行修复
3.1、方案一
# 查看当前版本
[root@localhost ~]# rpm -qa | grep openssh
openssh-8.7p1-38.el9.x86_64
openssh-clients-8.7p1-38.el9.x86_64
openssh-server-8.7p1-38.el9.x86_64
# 安装更新源
[root@localhost ~]# dnf install -y rocky-release-security
Last metadata expiration check: 1:16:01 ago on Wed 03 Jul 2024 09:08:38 AM CST.
Dependencies resolved.
================================================================================================================================================================================================================================================================
Package Architecture Version Repository Size
================================================================================================================================================================================================================================================================
Installing:
rocky-release-security noarch 9-4.el9 extras 9.5 k
Transaction Summary
================================================================================================================================================================================================================================================================
Install 1 Package
Total download size: 9.5 k
Installed size: 3.2 k
Downloading Packages:
rocky-release-security-9-4.el9.noarch.rpm 38 kB/s | 9.5 kB 00:00
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total 38 kB/s | 9.5 kB 00:00
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : rocky-release-security-9-4.el9.noarch 1/1
Running scriptlet: rocky-release-security-9-4.el9.noarch 1/1
Verifying : rocky-release-security-9-4.el9.noarch 1/1
Installed:
rocky-release-security-9-4.el9.noarch
Complete!
# 禁用 SIG/Security security-common repo
[root@localhost ~]# dnf config-manager --disable security-common
# 升级 openssh
[root@localhost ~]# dnf --enablerepo=security-common -y update openssh\*
Rocky Linux 9 - SIG Security Common 35 kB/s | 117 kB 00:03
Last metadata expiration check: 0:00:01 ago on Wed 03 Jul 2024 10:25:04 AM CST.
Dependencies resolved.
================================================================================================================================================================================================================================================================
Package Architecture Version Repository Size
================================================================================================================================================================================================================================================================
Upgrading:
openssh x86_64 8.7p1-38.el9_4.security.0.5 security-common 453 k
openssh-clients x86_64 8.7p1-38.el9_4.security.0.5 security-common 693 k
openssh-server x86_64 8.7p1-38.el9_4.security.0.5 security-common 435 k
Transaction Summary
================================================================================================================================================================================================================================================================
Upgrade 3 Packages
Total download size: 1.5 M
Downloading Packages:
(1/3): openssh-server-8.7p1-38.el9_4.security.0.5.x86_64.rpm 122 kB/s | 435 kB 00:03
(2/3): openssh-8.7p1-38.el9_4.security.0.5.x86_64.rpm 125 kB/s | 453 kB 00:03
(3/3): openssh-clients-8.7p1-38.el9_4.security.0.5.x86_64.rpm 171 kB/s | 693 kB 00:04
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total 331 kB/s | 1.5 MB 00:04
Rocky Linux 9 - SIG Security Common 1.6 MB/s | 1.7 kB 00:00
Importing GPG key 0x0FE8D526:
Userid : "Rocky Linux 9 SIGs - Security <releng@rockylinux.org>"
Fingerprint: 23DC 35EB E743 BAB0 CED2 1D20 8D79 B737 0FE8 D526
From : /etc/pki/rpm-gpg/RPM-GPG-KEY-Rocky-SIG-Security
Key imported successfully
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Running scriptlet: openssh-8.7p1-38.el9_4.security.0.5.x86_64 1/6
Upgrading : openssh-8.7p1-38.el9_4.security.0.5.x86_64 1/6
Running scriptlet: openssh-server-8.7p1-38.el9_4.security.0.5.x86_64 2/6
Upgrading : openssh-server-8.7p1-38.el9_4.security.0.5.x86_64 2/6
Running scriptlet: openssh-server-8.7p1-38.el9_4.security.0.5.x86_64 2/6
Upgrading : openssh-clients-8.7p1-38.el9_4.security.0.5.x86_64 3/6
Running scriptlet: openssh-clients-8.7p1-38.el9_4.security.0.5.x86_64 3/6
Running scriptlet: openssh-clients-8.7p1-38.el9.x86_64 4/6
Cleanup : openssh-clients-8.7p1-38.el9.x86_64 4/6
Running scriptlet: openssh-server-8.7p1-38.el9.x86_64 5/6
Cleanup : openssh-server-8.7p1-38.el9.x86_64 5/6
Running scriptlet: openssh-server-8.7p1-38.el9.x86_64 5/6
Cleanup : openssh-8.7p1-38.el9.x86_64 6/6
Running scriptlet: openssh-8.7p1-38.el9.x86_64 6/6
Verifying : openssh-server-8.7p1-38.el9_4.security.0.5.x86_64 1/6
Verifying : openssh-server-8.7p1-38.el9.x86_64 2/6
Verifying : openssh-clients-8.7p1-38.el9_4.security.0.5.x86_64 3/6
Verifying : openssh-clients-8.7p1-38.el9.x86_64 4/6
Verifying : openssh-8.7p1-38.el9_4.security.0.5.x86_64 5/6
Verifying : openssh-8.7p1-38.el9.x86_64 6/6
Upgraded:
openssh-8.7p1-38.el9_4.security.0.5.x86_64 openssh-clients-8.7p1-38.el9_4.security.0.5.x86_64 openssh-server-8.7p1-38.el9_4.security.0.5.x86_64
Complete!
# 确保 openssh-8.7p1-38.el9_4.security.0.5 已安装
[root@localhost ~]# rpm -q openssh
openssh-8.7p1-38.el9_4.security.0.5.x86_64
[root@localhost ~]# rpm -qa | grep openssh
openssh-8.7p1-38.el9_4.security.0.5.x86_64
openssh-server-8.7p1-38.el9_4.security.0.5.x86_64
openssh-clients-8.7p1-38.el9_4.security.0.5.x86_64
# 因为安装过程中会自动重启 sshd 服务，所以安装完后无需再手动重启服务
[root@localhost ~]# systemctl status sshd
● sshd.service - OpenSSH server daemon
Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled; preset: enabled)
Active: active (running) since Wed 2024-07-03 10:18:42 CST; 34s ago # 重启时间
Docs: man:sshd(8)
man:sshd_config(5)
Main PID: 64456 (sshd)
Tasks: 1 (limit: 48933)
Memory: 1.1M
CPU: 14ms
CGroup: /system.slice/sshd.service
└─64456 "sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startups"
Jul 03 10:18:42 localhost systemd[1]: Starting OpenSSH server daemon...
Jul 03 10:18:42 localhost sshd[64456]: Server listening on 0.0.0.0 port 22.
Jul 03 10:18:42 localhost systemd[1]: Started OpenSSH server daemon.
3.2、方案二
下载需要升级的安装包
编制安装脚本。
#!/bin/bash
set -e
echo -e "=======================================温馨提醒========================================="
echo -e "=== 1.本次安装升级OpenSSh9.8将同时升级OpenSSL版本至3.2.0，务必确保应用及产品兼容性。 ==="
echo -e "=== 2.建议提供其他能够链接至服务器的工具如Telnet防止升级失败导致服务器无法登录。 ==="
echo -e "=== 3.默认配置文件为/etc/ssh/sshd_config，若为自定义路径请修改脚本中SSH_CONFIG路径 ==="
echo -e "========================================================================================"
function OpenSSH_update() {
yum localinstall -y openssh-*
#cp -a /etc/ssh/ssh_host_* /tmp
#rm -rf /etc/ssh/ssh_host_*
#默认配置文件
SSH_CONFIG=/etc/ssh/sshd_config
COUNTERS=0
while [ ! -f ${SSH_CONFIG} ] && [ ${COUNTERS} -lt 3 ];
do
echo -e "默认配置文件${SSH_CONFIG}不存在，请确认sshd_config配置文件位置。"
read -p "请输入sshd_config文件路径，(例：/etc/ssh/sshd_config) :" SSH_CONFIG
COUNTERS=$((COUNTERS+1))
done
if [ ${COUNTERS} -eq 3 ]; then
echo "已经达到最大重试次数，升级脚本自动退出，请确认配置文件路径后在次运行脚本。"
exit 1
fi
echo -e "默认配置文件为${SSH_CONFIG}"
#备份配置文件到/tmp
cp -a ${SSH_CONFIG} /tmp
#表示指定将接受用于基于主机的身份验证的密钥类型。
if ! grep -q '^PubkeyAcceptedAlgorithms' "${SSH_CONFIG}"; then
sed -i '$a\PubkeyAcceptedAlgorithms +ssh-rsa' "${SSH_CONFIG}"
fi
# 表示指定公钥认证允许的密钥类型。
if ! grep -q '^PubkeyAcceptedKeyTypes' "${SSH_CONFIG}"; then
sed -i '$a\PubkeyAcceptedKeyTypes +ssh-rsa' "${SSH_CONFIG}"
fi
# 表示指定服务器提供的主机密钥算法。
if ! grep -q '^HostKeyAlgorithms' "${SSH_CONFIG}"; then
sed -i '$a\HostKeyAlgorithms +ssh-rsa' "${SSH_CONFIG}"
fi
#PubkeyAcceptedKeyTypes +ssh-rsa
#HostKeyAlgorithms +ssh-rsa
echo -e "重启sshd服务......"
systemctl restart sshd
if [ -n "$(systemctl status sshd | grep "active (running)")" ]; then
echo "OpenSSH 升级成功"
exit 0
else
echo "重启sshd服务异常，请手动检查错误信息（systemctl status sshd -l）"
exit 1
fi
}
function main() {
while true
do
read -p "请确认是否继续升级操作(Y/N)" yn
case ${yn} in
[Yy] ) echo "开始升级......"; OpenSSH_update;;
[Nn] ) echo "退出"; exit 0; break;;
* ) echo "请输入Yy/Nn";;
esac
done
}
main
将安装包和脚本上传至服务器，运行脚本。
4、总结
互联网接入环境中推荐方案一，离线情况下使用方案二操作。
5、参考
Rocky Linux 9 & RedHat 系 OpenSSH CVE-2024-6387 漏洞快速修复
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