Passionate about Linux hardening, compliance, security management and new technologies.

Docker Security: How Containers (Not) Help You

Docker and Security Things about containers Security is hot and so is Docker. During the last years Docker has become one of quickest growing container techniques for Linux. While system virtualization continues to grow, the technology allowing flexible containers is growing even faster and starting to compete. In this article we have a look how containers may help you with you security needs and Docker security in particular. How containers work Containers are like “chroot” on steroids. Where chroot is […]

Read more

Linux Security Scanning for Dummies

Linux Security Scanning for Dummies Every system needs some level of protection. Still, many people simply forget to do it, or can not find the time to properly do it. To be as efficient and effective as possible, let’s take at a structured way for security scanning your Linux machines. The 5 dummy steps are: 1. Focus on risk Like not every company is a bank, our systems are not all part of a top secret mission. We have to […]

Read more

Protect against the BEAST attack in Nginx

Protect against the BEAST attack in Nginx   What is this BEAST? BEAST, or “Browser Exploit Against SSL/TLS” is an attack against the cipher block chaining (CBC) method used with SSL/TLS. The weakness was discovered in 2002, but finally proven in 2011 by security researchers Thai Duong and Juliano Rizzo. With real proof of concept code, they showed it was no longer a theoretical attack. To successfully perform the BEAST attack, there are some conditions which needs to be met: Vulnerable version of […]

Read more

Monitor for File System Changes on Linux

Monitor for File System Changes The most important areas with information security are preventing some events from occurring and detecting it if something still happens. Unfortunately most companies forget to put enough effort in detection unauthorized activities. In this article we have a special look at monitoring your file system, to detect changes to your critical system files and their configuration files. Method 1: File Integrity tools The first method is monitoring file changes with the help of specific tools. […]

Read more

Linux security: Reviewing log files

Linux security: Reviewing log files Log files are the precious collection of system events. Still many people don’t use them, until it is really needed. Let’s go from the reactive use of log files to a proactive stance. The Logging Dilemma Capturing events helps in troubleshooting. By defining what events are ignored and which ones are logged, we get a quick overview on the status of a system. The dilemma is usually in how much logging is enough to get […]

Read more

5 things you didn’t know about shell scripting

Our security auditing tool Lynis is a toolkit consisting of several shell scripts. Many users of the software actually never realized it was written as a bunch of shells scripts. Now that the secret is out, it is time to learn why we used shell scripting. Here are 5 reasons! 1. Shell scripting is powerful Yes, people asked us why our tool Lynis was not written in Perl, Python, Ruby, C++ etc.. But honestly, why would we? It is portable, […]

Read more

Configure HSTS (HTTP Strict Transport Security) for Apache and Nginx

HSTS configuration for Apache and Nginx HTTP Strict Transport Security (or HSTS) is a security capability to force web clients using HTTPS. The idea behind HSTS is that clients which always should communicate as safely as possible. At achieve this, the web server and web browser will prefer the HTTPS protocol instead of HTTP. Benefits The clear benefit of “forcing” a client to use HTTPS directly, is decreasing the risk of sharing any sensitive information via a protocol which can […]

Read more

Check for a required reboot on Debian and Ubuntu systems

Required restart required? Administrators of Debian-based systems know they have to reboot their systems, just like any other Linux distribution. However, why is the reboot needed? Could we monitor for which systems need an actual reboot? Required reboot Software can contain issues, which we call bugs. Most bugs are just annoying if you encounter them and can be fixed by upgrading to a newer version of the software. Other bugs are special in the way that they may leak sensitive […]

Read more

How and why Linux daemons drop privileges

How and why Linux daemons drop privileges In this article we have a look at the privileges of Linux daemons and dropping privileges in particular. The samples provided are in C. Why drop privileges? Some daemons need root permissions to start. This happens for example when a daemon wants to bind to a low port (<1024). However running network based daemons with root permissions is considered to be a serious risk. In case of compromise of the process, an attacker […]

Read more

Security Program: Implementing Linux Security

Security Program: Implementing Linux Security Information security is possibly one of the hardest subjects in IT. Doing too less and you risk of security breaches. Doing too much will restrict the core businesses of your organization. With a proper security program, implementing Linux security can be greatly simplified. By having a structured approach, the strength of the defenses will increase, while risks decrease. In this article, we have a look at how to properly prepare security projects and changes. This […]

Read more

Security Audits – How to Prioritize Audit Findings

Security Audits – How to Prioritize Audit Findings Technical audits or vulnerability scans will reveal a lot of findings. They can be overwhelmed and forcing the reviewer to freeze, not knowing where to start. To overcome this issue, we should prioritize the findings and determine the consequences of each finding for our company. While an open directory listing on a web server might in one situation not be preferred, it would make sense for others. It is the context which […]

Read more

Do NOT use Linux hardening checklists for your servers

Do NOT use Linux hardening checklists for your servers Quality is an interesting word. It describes, well, the quality of something. Quality is just another word for how well can you repeat something. The goal is to get each time exactly the same result. Whenever it’s a physical product, or rolling out a new Linux system, you want great quality. One method to increase quality is using checklists. However we strongly advice against using Linux hardening checklists.. But checklists are […]

Read more

How to audit AIX Unix systems with Lynis

How to audit AIX Unix systems with Lynis Each system is as strong as its weakest link. Also for systems running on AIX this rule applies. Therefore a regular audit can help finding the weakest links. Next step is then the fortification of these weakened areas and implementing system hardening measures. What to audit? There is a lot to look for when auditing a system running AIX. Let’s have a look at the most important areas. File systems Monitor alterations […]

Read more

How to deal with Lynis suggestions?

How to deal with Lynis suggestions? After finishing an audit with Lynis, the screen is usually filled with a lot of suggestions. Most users don’t know where to start with hardening and how to deal with these Lynis suggestions in particular. We provide you some tips! Before we start, we strongly suggest to use the latest version of Lynis. If you are using an outdated version from the software repositories, the output could be slightly different. The latest version can […]

Read more

Linux Security for DevOps

Linux Security for DevOps During the last years the role of DevOps evolved. This person could be described as the hybrid: a system administrator with development skills, or the developer which is also infrastructure savvy. With Linux and so many available tooling, it is becoming easier for people to learn both development and managing infrastructures. We are especially interested in Linux security for DevOps and what they can apply. Automation is key Repeating work is not only boring, but also […]

Read more
1101112131415