Linux security myths

Myth busting: Linux security As the author of Lynis, I have to run several Linux systems for testing Linux security defenses. And if you do something long enough, some get to see you as a Linux security expert. When that happens, you get asked questions. Surprisingly they are often related to some of the myths. Time to share a few I got asked. If you received this link from me directly, then most likely you asked one :) Linux systems […]

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GDPR Compliance: Technical Requirements for Linux Systems

GDPR for Linux systems What is GDPR? The General Data Protection Regulation (GDPR) is a regulation to protect data stored about individuals from the European Union. When speaking about stored data, it includes the handling of data at any given time, from entry to data deletion. One of the important parts is the right to ‘know’. That means that individuals can ask what data is stored about them. Another request they may make is that this data is deleted. You may know […]

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Configure the minimum password length on Linux systems

Linux and password strength One of the options to improve password security is by setting a minimum length. This prevents users from choosing easy passwords. As part of Linux system hardening, you don’t want your passwords to be cracked too quickly by modern password crackers. Configuration Login settings The first area where you can set a password length is in /etc/login.defs. The related setting is PASS_MINLEN and already tells us it is about the minimum length of a password. Modern Linux […]

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Beginners Guide to nftables Traffic Filtering

Traffic filtering with nftables Many Linux administrators became familiar with iptables and ip6tables. Less familiar are tools like arptables and ebtables. Meet the successor of them all: nftables, a packet filtering framework, with the goal to replace all the previous ones. After reading this guide you will be able to configure your own firewall configuration. Step by step we will show how nftables work. Although no knowledge of iptables is needed, we will share some differences with iptables where applicable. […]

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The purpose of the /etc/networks file

What is /etc/networks file? Also wondering what particular files do on Linux? One of those files we recently rediscovered during auditing is the /etc/networks file. For some reason it was always there, yet we never change it. When looking at the man page of networks(5) we learn its purpose (almost instantly): It translates between IP ranges and network names It is used for tools like netstat and route It only works on class A, B, or C networks It does […]

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Livepatch: Linux kernel updates without rebooting

Maximize uptime with livepatch If you run a Linux server, software patching is a task that will have to be performed on a weekly (or daily) basis. Although most programs can be auto-restarted with a tool like needrestart, there is one exception: the kernel. Wouldn’t it be a nice if we could patch the kernel, without the mandatory reboot? Here is livepatch, the feature of the Linux kernel that makes it possible. Kernel Live Patching Core Although there are more […]

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Interview: MalwareMustDie and their Linux malware research

Linux malware, research, and more With great pleasure, we interviewed unixfreaxjp. He is the leader and founder of the malware research group MalwareMustDie. We want to learn about their activities, Linux malware, and useful skills for security professionals. Keep reading! Interview MalwareMustDie About the MalwareMustDie organization So for those never heard about MalwareMustDie, can you tell us who you are? As stated on our web site. MalwareMustDie, is a white-hat anti cybercrime security research workgroup. launched in August 2012, is an Non […]

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How to see the version of Oracle Linux

Determine Oracle Linux version Oracle Linux is based on Red Hat Enterprise Linux. At first, it may be confusing to determine what specific operating system is running. This is because both have the /etc/redhat-release file. If that file exists, use the cat command to display the contents. Next step is to determine if there is a /etc/oracle-release file as well. If so, then you can be sure that Oracle Linux is running. cat /etc/oracle-release Sample output might be: Oracle Linux Server release […]

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