Dear Customer,Are you running a Linux based operating system? If you are running an operating system such as CentOS, Red Hat, Debian, or Ubuntu you are most likely vulnerable to a recent security exploit found in the Linux kernel.We are always following the latest news and events when it comes to server security, and we wanted to alert you to the presence of a particularly serious vulnerability in Linux based operating systems called Dirty Cow. Dirty Cow is a privilege escalation vulnerability, which means it can be used to gain higher levels of access on your server without permission.You can find more information about the vulnerability online, for example this article is fairly comprehensive: https://www.linux.com/blog/how-bad-dirty-cowProvided your distribution has released an updated kernel to fix Dirty Cow, fixing this issue is as simple as installing all of your available updates and rebooting your server in order to load the new kernel.--- How Can I Tell If I Am Vulnerable? ---To tell if you are vulnerable to Dirty Cow, simply check your kernel version.** CentOS Red Hat **On CentOS, you can run this command to use the script provided by Red Hat for RHEL to test if you are vulnerable. The output from the command will tell you if you are vulnerable or not.curl -sq https://access.redhat.com/sites/default/files/rh-cve-2016-5195_1.sh | bash** Debian Ubuntu **You can obtain your kernel version by running this command:uname -rvThen compare it to this list of kernel versions. If your kernel version is earlier than the version listed below (a lower number), you are vulnerable.3.16.36-1+deb8u2 for Debian 83.2.82-1 for Debian 74.7.8-1 for Debian unstable4.8.0-26.28 for Ubuntu 16.104.4.0-45.66 for Ubuntu 16.04 LTS3.13.0-100.147 for Ubuntu 14.04 LTS3.2.0-113.155 for Ubuntu 12.04 LTS--- How Do I Patch My System? ---The below commands will help you to upgrade all software on your server. Please note that these commands will upgrade everything - if you only want to patch for Dirty Cow but you do not want to upgrade other software on your server, you will only need to update the Linux kernel packages.If you are running a Red Hat based Linux distribution such as CentOS, you can update your system by running these commands:sudo yum update -yrebootIf you are running a Debian based Linux distribution such as Ubuntu, you can update your system by running these commands:sudo apt-get updatesudo apt-get dist-upgrade -yreboot