After the CentOS 7 EOL, Yum update showing error while updating the packages. To resolve the issue you can mass update all .repo files:
Run the following Command One by one on your CentOS 7 Server. Then run the YUM UPdate.
sed -i s/mirror.centos.org/vault.centos.org/g /etc/yum.repos.d/*.repo
sed -i s/^#.*baseurl=http/baseurl=http/g /etc/yum.repos.d/*.repo
sed -i s/^mirrorlist=http/#mirrorlist=http/g /etc/yum.repos.d/*.repo