Dirty Cow exploit
The Dirty Cow exploit that affects the Linux kernel may affect your VM. If you allow multiple users to log into your VMs and you do not expect them to have root access, they may use thie Dirty Cow exploit to gain root access anyway. You may want to prevent that.
Our AppMarket images have been updated on 26-10-2016.
Ubuntu
As explained in their security/upgrades pagina, you are advised to run at least:
sudo apt-get update && sudo apt-get dist-upgrade
If you are running a 14.04 version of Ubuntu with a 4.2 kernel (check the output of uname -rv) you will also need to upgrade to the xenial kernel stack:
sudo apt-get install --install-recommends linux-generic-lts-xenial
When the upgrades are finished, you will have to reboot so that you start using the new kernel.
Details on Ubuntu-related pages:
CentOS
For both Centos 6.x and 7.x updated kernels have been made available by RedHat. you will be able to install it with:
sudo yum update