Server Security: Applying Security Updates to Your EC2 Instance

Enhance the server security of a Red Hat Enterprise Linux EC2 instance by monitoring and applying system updates.

This is the first part of our Server Security on AWS series. In this series, we will explore some ways to enhance the security of a Red Hat Enterprise Linux EC2 instance. We may also touch on Amazon Linux where appropriate. This will by no means be an exhaustive list of the things you can do to harden and enhance the security posture of your cluster of EC2 instances, but it should be sufficient to get you moving in the right direction.

In this article, we will look at installing security updates and how, by default, Amazon Linux and Red Hat Enterprise Linux differ.

Server Security: monitoring system notices

When you launch an Amazon Linux instance for the first time, you will see the message of the day (MOTD). Amazon Linux will install both the critical and important security updates at launch time by default.

       __|  __|_  )
       _|  (     /   Amazon Linux AMI
      ___|\___|___|
https://aws.amazon.com/amazon-linux-ami/2015.09-release-notes/

If (right after the release notes link) your MOTD message indicates that you have additional security updates to install, they tend to be of a lower severity, but you should still install them as soon as you can.

# yum update --security

Right now there are no security updates I need to install myself. If there were, they would be generated by the 70-available-updates script:

# cat /etc/update-motd.d/70-available-updates | head -5
#!/bin/bash
# Possible summaries include:
# No packages needed for security; %d packages available
# %d package(s) needed[ (+%d related)] for security, out of %d available
# There are [[%d security update(s)[ out of ]%d total update(s)]] available

On Red Hat Enterprise Linux, you have to install the security updates yourself. RHEL does not install any critical or important security updates automatically. Using yum update, I’m shown a handful of packages that I should update in my newly launched instance:

# yum update --security | egrep -e '^(I|U).*\)$'
Install   1 Package  (+1 Dependent package)
Upgrade  23 Packages (+4 Dependent packages)

Server Security: applying updates

Running yum update --security lets you apply all the available security updates and ignore any other non-security updates. This is to ensure that you do not introduce additional – and unnecessary – changes to your EC2 instance, especially if stability is a priority.

To keep up with the security updates you may have to apply on Amazon Linux, you can watch the security bulletins as they are published at the Amazon Linux AMI Security Centre.

If you have a specific RHEL CVE (Common Vulnerabilities and Exposures) ID you would like to explore, you can query it using Red Hat’s CVE Database.

This was just a quick start to whet your appetite for more. In our next article, we will explore using firewall-cmd to configure firewall rules in your Red Hat Enterprise Linux 7 EC2 instance. You might also like to take Cloud Academy’s Introduction to Security Best Practices and Linux Security courses.

Any thoughts? Why not share them in the comments below.

Avatar

Written by

Eugene Teo

Eugene Teo is a director of security at a US-based technology company. He is interested in applying machine learning techniques to solve problems in the security domain.


Related Posts

Amanda Cross
Amanda Cross
— April 9, 2021

New Content: Platforms, Programming, and DevOps – Something for Everyone

This month our team of expert certification specialists released three new or updated learning paths, 16 courses, 13 hands-on labs, and four lab challenges! New content on Cloud Academy You can always visit our Content Roadmap to see what’s just released as well as what’s coming soon....

Read more
  • alibaba
  • AWS
  • Azure
  • DevOps
  • Google Cloud Platform
  • programming
  • Security
Luca Casartelli
Luca Casartelli
— March 31, 2021

Mastering AWS Organizations Service Control Policies

Service Control Policies (SCPs) are IAM-like policies to manage permissions in AWS Organizations. SCPs restrict the actions allowed for accounts within the organization making each one of them compliant with your guidelines. SCPs are not meant to grant permissions; you should consider ...

Read more
  • AWS
  • Organizations
  • SCP
Amanda Cross
Amanda Cross
— March 12, 2021

New Content: Focus on DevOps and Programming Content this Month

This month our team of expert certification specialists released 12 new or updated learning paths, 15 courses, 25 hands-on labs, and four lab challenges! New content on Cloud Academy You can always visit our Content Roadmap to see what’s just released as well as what’s coming soon. Ja...

Read more
  • alibaba
  • AWS
  • Azure
  • DevOps
  • Google Cloud Platform
  • programming
Amanda Cross
Amanda Cross
— February 12, 2021

New Content: Get Ready for the CISM Cert Exam & Learn About Alibaba, Plus All the AWS, GCP, and Azure Courses You Know You Can Count On

This month our team of intrepid certification specialists released five learning paths, seven courses, 19 hands-on labs, and three lab challenges!  One particularly interesting new learning path is Certified Information Security Manager (CISM) Foundations. After completing this learn...

Read more
  • alibaba
  • AWS
  • Azure
  • cism
  • DevOps
  • Google Cloud Platform
  • programming
Avatar
Cloud Academy Team
— January 31, 2021

Which Certifications Should I Get?

The old AWS slogan, “Cloud is the new normal” is indeed a reality today. Really, cloud has been the new normal for a while now and getting credentials has become an increasingly effective way to quickly showcase your abilities to recruiters and companies. With all that in mind, the s...

Read more
  • AWS
  • Azure
  • Certifications
  • Cloud Computing
  • Google Cloud Platform
Avatar
Andrew Larkin
— January 31, 2021

The 12 AWS Certifications: Which is Right for You and Your Team?

As companies increasingly shift workloads to the public cloud, cloud computing has moved from a nice-to-have to a core competency in the enterprise. This shift requires a new set of skills to design, deploy, and manage applications in cloud computing. As the market leader and most ma...

Read more
  • AWS
  • AWS Certifications
Avatar
Stuart Scott
— January 29, 2021

AWS Certified Solutions Architect Associate: A Study Guide

Want to take a really impactful step in your technical career? Explore the AWS Solutions Architect Associate certificate. Its new version (SAA-C02) was released on March 23, 2020. The AWS Solutions Architect - Associate Certification (or Sol Arch Associate for short) offers some ...

Read more
  • AWS
  • AWS Certifications
  • AWS Certified Solutions Architect Associate
Amanda Cross
Amanda Cross
— January 7, 2021

New Content: AWS Terraform, Java Programming Lab Challenges, Azure DP-900 & DP-300 Certification Exam Prep, Plus Plenty More Amazon, Google, Microsoft, and Big Data Courses

This month our Content Team continues building the catalog of courses for everyone learning about AWS, GCP, and Microsoft Azure. In addition, this month’s updates include several Java programming lab challenges and a couple of courses on big data. In total, we released five new learning...

Read more
  • AWS
  • Azure
  • DevOps
  • Google Cloud Platform
  • Machine Learning
  • programming
Avatar
Stuart Scott
— December 17, 2020

Where Should You Be Focusing Your AWS Security Efforts?

Another day, another re:Invent session! This time I listened to Stephen Schmidt’s session, “AWS Security: Where we've been, where we're going.” Amongst covering the highlights of AWS security during 2020, a number of newly added AWS features/services were discussed, including: AWS Audit...

Read more
  • AWS
  • AWS re:Invent
  • cloud security
Joe Nemer
Joe Nemer
— December 4, 2020

AWS re:Invent: 2020 Keynote Top Highlights and More

We’ve gotten through the first five days of the special all-virtual 2020 edition of AWS re:Invent. It’s always a really exciting time for practitioners in the field to see what features and services AWS has cooked up for the year ahead.  This year’s conference is a marathon and not a...

Read more
  • AWS
  • AWS Glue Elastic Views
  • AWS re:Invent
Bryony Harrower
Bryony Harrower
— November 6, 2020

WARNING: Great Cloud Content Ahead

At Cloud Academy, content is at the heart of what we do. We work with the world’s leading cloud and operations teams to develop video courses and learning paths that accelerate teams and drive digital transformation. First and foremost, we listen to our customers’ needs and we stay ahea...

Read more
  • AWS
  • Azure
  • content roadmap
  • GCP
Joe Nemer
Joe Nemer
— October 25, 2020

Excelling in AWS, Azure, and Beyond – How Danut Prisacaru Prepares for the Future

Meet Danut Prisacaru. Danut has been a Software Architect for the past 10 years and has been involved in Software Engineering for 30 years. He’s passionate about software and learning, and jokes that coding is basically the only thing he can do well (!). We think his enthusiasm shines t...

Read more
  • AWS
  • careers
  • champions
  • upskilling