I think lots of people have heard about this and you might be curious about it too. So your first question may be “What is Dirty Cow?”.
Basically “Dirty Cow” is vulnerability of Linux kernel system. It may allow anonymous user to access the shared data and is a COW (Copy on Write) breakage.
If you got alert from your hosting company or even if not, you need to immediately discuss with your hosting service provider and must apply patches / fixes related to it and make sure that rights and privileges that you have provided are in proper place and not removed / modified.
Now let’s try to understand what Dirty cow is?
Your first thought / question may be “Why it’s named Dirty Cow?” Answer is, as it’s related to Copy of write breakage of Linux kernel memory subsystem so as a short form it’s called as COW. Also the important thing lets thanks “Phil Oester” who found the bug and reported it. The bug was there in the Linux kernel since version 2.6.22 which was released in September 2007 but now the bug has been fixed and patches are available to fix this in Linux kernel versions 4.8.3, 4.7.9, 4.4.26 and newer.
Now how its attacks the harms the system?
Remote attackers can get access of files and shared items due to this bug and the most IMPORTANT thing is that either on server or attack itself will not leave any clue and you can’t track this access. Also as “Dirty COW” was hidden in the code for more than nine years and it’s confirmed that if you are using any older version of Linux or android released in the past then you need to check and take serious action on it.
So I think this blog gives you fair idea of this serious DIRTY COW issue and now I suggest you to start checking your server and details related to it and ask your hosting service providers to do check on server and install all patches / upgrade related to this as early as possible.