Firejail is a Linux security SUID program that drastically reduces the risk of security breaches by sandboxing the running environment of untrusted applications. Firejail achieves this by using Linux namespaces and seccomp-bpf which allows the attaching of a system call filter to a process and all its descendants, thus reducing the attack surface of the kernel.
With Firejail installed, you can then launch applications from the command line, such that they have a private view of globally-shared kernel resources–such as the network stack. With this addition to your Linux platform, you’ll gain a heightened level of security to an already secure environment.
Firejail is not limited to graphical applications. In fact, Firejail can sandbox servers, GUI tools, and even user login sessions.
Believe it or not, Firejail is incredibly easy to use. I’m going to walk you through the process of installing and using Firejail.
What makes Firejail so special it qualifies for inclusion in our Essential System Tools feature? Above all, it puts users first.
It’s really easy to install and use. More time to spend actually using software. Most people won’t need any custom configuration. There’s a wide range of software which come with sandbox profiles.
The software helps to reduce the risk of security breaches. It’s lightweight and while it uses CPU cycles, the overhead is remarkably low. Firejail sandboxes do not each run their own copy of a full-blown operating system. Instead they operate in a resource-isolated environment created by standard facilities of your system’s existing Linux kernel. As such, despite the high level of protection offered, the overhead of running a Firejail sandbox is extremely low. So your software, including games, run at full steam, unlike a full virtualisation environment.
Firejail is an excellent tool for the security conscious. While it adds a layer of protection, you should use it with other security tools. We use it mainly for web browsing, and to lock down services.
Firejail is a powerful tool which can be use to sandboxing lot of applications. By default Firejail provides profiles for Chrome, Firefox, Telegram and other famous applications. Wireshark is still missing.
We want to limit the interfaces a user can sniff. To be more specific, we want users capture from bridges interfaces only.
Video by Null Byte, Youtube
Video by Joe McEntire, Youtube.
How to set up the most ridiculously secure browser I’ve ever seen! Uses Debian 9, Firefox 58.0.2, and Firejail
Sometimes you may want to use applications that have not been well tested in different environments, yet you must use them. In such cases, it is normal to be concerned about the security of your system. One thing that can be done in Linux is to use applications in a sandbox.
“Sandboxing” is the ability to run application in a limited environment. That way the application is provided a tighten amount of resources, needed to run. Thanks to application called Firejail, you can safely run untrusted applications in Linux.
Firejail is a SUID (Set Owner User ID) application that decrease the exposure of security breaches by limiting the running environment of untrusted programs using Linux namespaces and seccomp-bpf.
It makes a process and all its descendants to have their own secret view of the globally shared kernel resources, such as the network stack, process table, mount table.
This document is aimed at teams of systems administrators who use Linux workstations to access and manage your project’s IT infrastructure.
If your systems administrators are remote workers, you may use this set of guidelines to help ensure that their workstations pass core security requirements in order to reduce the risk that they become attack vectors against the rest of your IT infrastructure.
Even if your systems administrators are not remote workers, chances are that they perform a lot of their work either from a portable laptop in a work environment, or set up their home systems to access the work infrastructure for after-hours/emergency support. In either case, you can adapt this set of recommendations to suit your environment.
Firejail Download page
This guide will be a beginner-friendly walthrough of hardening your Linux system. This does not have to be done all at once. Feel free to ease into it–or take it even further as I’ll also be providing recommendations for more advanced users throughout. Just go at your own pace, crank up some music, and makeit your own.
My goals for this guide:
Demonstrate how to achieve excellent security without impeding usability
Introduce newbies to Linux security basics
Provide plenty of information for more seasoned Linux users
Make the hardening process smooth and streamlined
Once you’ve installed Ubuntu with security in mind and reduced the possibility of network attacks on your system, you can start thinking about security on an application level. In the event that a malicious file is opened on your system, will an attacker be able to access every file on the computer? The chances are much slimmer if you put the proper defenses in place.
In this third part to our mini-series on strengthening your primary Ubuntu installation, you’ll learn how Ubuntu package repositories work, which repos you should avoid, and how to update. Also, you’ll see how to import additional AppArmor profiles to limit resources that apps can use, as well as create sandboxes to completely isolate unsafe applications from the operating system.
I am very fond of combining both VPN and Firejail on my travel laptop (where I cannot use QubesOS), but I have recently discovered that I was leaving myself exposed to online tracking via so-called “WebRTC leaks.” My VPN provider offers a convenient testing page to see how well protected my connection is, and they very helpfully alerted me to this problem: