What is Kernel?

The kernel is the central module of a server OS. The core that provides basic services is for all other parts of the operating system.

Why you need to update kernel?
Meltdown and Spectre exploit processor vulnerabilities allow programs to steal data which is currently process on the computer. You may update those release update to reduce the risk.

Below steps how to perform:

A) Linux OS:

Apply the kernel version update according to your current OS version:

OS Version: CL6
Kernel version that fixed the issue: 2.6.32-896.16.1.lve1.4.49.el6

Command to run:

yum clean all && yum update kernel-firmware && yum install kernel-2.6.32-896.16.1.lve1.4.49.el6

OS Version: CL7
Kernel version that fixed the issue: 3.10.0-714.10.2.lve1.5.8.el7

Command to run:

yum clean all –enablerepo=cloudlinux-updates-testing && yum update linux-firmware microcode_ctl && yum install kernel-3.10.0-714.10.2.lve1.5.8.el7 –enablerepo=cloudlinux-updates-testing

OS Version: Centos6
Kernel version that fixed the issue: 2.6.32-696.18.7.el6.x86_64

Command to run: 
yum clean all; yum update kernel-2.6.32-696.18.7.el6.x86_64 

OS Version: Centos7
Kernel version that fixed the issue: 3.10.0-693.11.6.el7.x86_64

Command to run: 
yum clean all; yum update kernel-3.10.0-693.11.6.el7.x86_64

How to verify that you run the update correctly?

Inside your SSH, run the following command to check:

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cat /etc/redhat-release
uname -r     

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B) Windows OS:

Apply the Windows operating system update according to your current server version:

Windows Server 2008 R2

Steps to update:https://support.microsoft.com/en-us/help/4056897

Windows Server 2012 R2

Steps to update:https://support.microsoft.com/en-us/help/4056898

Windows Server 2016

Steps to update:https://support.microsoft.com/en-us/help/4056890

How to verify that you run the update correctly?

Speculation Control Validation PowerShell Script:

https://github.com/microsoft/SpeculationControlhttps://gallery.technet.microsoft.com/scriptcenter/Speculation-Control-e36f0050