1. 查看系统版本

[root@localhost ~]# cat /etc/redhat-release

2. 查看polkit是否为安全版本

[root@localhost ~]# rpm -qa polkit 

3. 配置 aliyun yum源，如有可⽤yum源，此步骤可以省略(centos8官方源已下线，需要切换centos-vault源)

[root@localhost ~]# cd /etc/yum.repos.d/

备份yum源

[root@localhost yum.repos.d]# ls 
[root@localhost yum.repos.d]# mkdir backup
[root@localhost yum.repos.d]# mv *.repo backup/

更新aliyun yum源

[root@localhost yum.repos.d]# wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo
[root@localhost yum.repos.d]# yum clean all && yum makecache

4. 升级到安全本版或最⾼版本

[root@localhost yum.repos.d]# yum update polkit -y

5. 再次查看polkit版本

6. 参考资料：
   https://wenku.baidu.com/view/5db8c89cc47da26925c52cc58bd63186bceb92f2.html

https://www.alibabacloud.com/help/zh/elastic-compute-service/latest/vulnerability-announcement-or-linux-polkit-privilege-escalation-vulnerability

https://developer.aliyun.com/mirror/centos?spm=a2c6h.13651102.0.0.3e221b11KerVXv