Cybersecurity in the Age of the Machine
As zero-day exploits become increasingly common, keeping the kernel up to date is a top priority.
In CentOS 6.x/7.x and RHEL 6x./7.x, upgrading the Linux Kernel is a painful procedure which requires about a dozen steps. On Fedora, all it takes is a time-saving two-liner. You don’t need to concern yourself with the configuration of the grub boot manager, which is a frequent source of trouble on CentOS and RHEL.
[Updated 2018-06-10] This post explains how to set up robust security headers in NGINX to protect your web application from malicious payloads and other forms of attacks. Choose your HTTP(S) headers wisely.
In the age of cyber warfare, being paranoid is the only reasonable attitude and that means, among other things, being paranoid about software updates.
If you launch an instance from the official CentOS or RHEL 7.x AMI on AWS, you will be running kernel 3.1 as of this writing. That’s not a good idea. You can easily take advantage of improved security features of newer kernels that are already available in a stable release. The renowned Linux kernel maintainer Greg Kroah-Hartman released the Linux Kernel 4.14.15, which includes important fixes for Spectre & Meltdown. Here is how to update your Linux kernel from 3.1 to 4.16.11 in place.
[Updated 2018-06-11.] You can assign multiple IP addresses to an EC 2 instance. Here is a brief summary that will get you started on using the most recent AWS capabilities.