Problem

The beginning of 2018, several vulnerabilities in most used CPUs were revealed . Taking advantage of certain processor performance optimizations, these vulnerabilities make it possible for hackers to force applications into showing the contents of system and application memory when manipulated correctly. These attacks work because the normal privileges checking behavior.

Should I do something

Patches to secure against Meltdown were released from most OS vendors. So it's best to be up to date with the software on your system. Be sure that you have the latest software updates.

Solution update your system

First of all you need to know what is your system:

lsb_release -a
cat /etc/*release

the result would be :

DISTRIB_ID=LinuxMint

DISTRIB_RELEASE=17.2
DISTRIB_CODENAME=rafaela

then you need to check your kernel version

uname -r

You should receive a result similar to the following:

4.14.14-x86_64

The output can be interpreted with the following key:

4 – Kernel Version
14 – Major Revision
14 – Minor Revision

These are the distributions that have released kernel updates:

Ubuntu 17.10: kernel 4.13.0-25-generic
Ubuntu 16.04: kernel 4.4.0-109-generic
Ubuntu 14.04: kernel 3.13.0-139-generic

If your kernel is updated to at least the version corresponding to the above, so you have some protection.

Otherwise you need to update your system by:

    sudo apt-get update
    sudo apt-get dist-upgrade

Note: Please be sure to copy and back up valuable information before updates (in general).

Once you apply the updates you will need to reboot your machine.

Read more

What is Ubuntu's status on the Meltdown and Spectre vulnerabilities?

Spectre And Meltdown