You may have seen in the news recently about a bug in the Linux Kernel called Dirty COW – it’s a vulnerability that effects the ‘copy-on-write’ mechanism in Linux, aka COW. This exploit can be used to gain full control over a device running a version of Linux; this includes Android phones, web servers, and even the Raspberry Pi.
How to fix it
You don’t need to worry though as a patch for Raspbian Jessie to fix Dirty COW has already been released, and you can get it right now. Open up the terminal and type the following:
sudo apt-get update sudo apt-get install raspberrypi-kernel
Once the install is done, make sure to reboot your Raspberry Pi and you'll be Dirty COW free!