Dirty COW is an underlying issue was a race condition in the way kernel handles copy-on-write (COW).

More information can be found on CVE-2016-5195.

To find out if your server is affected, check your kernel version.

uname -rv

You'll see output like this:

Output

4.4.0-42-generic #62-Ubuntu SMP Fri Oct 7 23:11:45 UTC 2016

If your version is earlier than the following, you are affected:

• 4.8.0-26.28 for Ubuntu 16.10
• 4.4.0-45.66 for Ubuntu 16.04 LTS
• 3.13.0-100.147 for Ubuntu 14.04 LTS
• 3.2.0-113.155 for Ubuntu 12.04 LTS
• 3.16.36-1+deb8u2 for Debian 8
• 3.2.82-1 for Debian 7
• 4.7.8-1 for Debian unstable

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

<WRAP info> On Redhat use:

sudo yum update kernel </code>

Then reboot.