8.7 KiB
| title | icon |
|---|---|
| Linux Overview | fontawesome/brands/linux |
It is often believed that open source software is inherently secure because the source code is available. There is an expectation that community verification occurs regularly; however, this isn’t always the case. It does depend on a number of factors, such as project activity, developer experience, level of rigour applied to code reviews, and how often attention is given to specific parts of the codebase that may go untouched for years.
At the moment, desktop GNU/Linux does have some areas that could be better improved when compared to their proprietary counterparts, e.g:
- A verified boot chain, unlike Apple’s Secure Boot (with Secure Enclave), Android’s Verified Boot or Microsoft Windows’s boot process with TPM. These features and hardware technologies can all help prevent persistent tampering by malware or evil maid attacks
- Strong sandboxing solution such as that found in MacOS, ChromeOS, and Android. Commonly used Linux sandboxing solutions such as Flatpak and Firejail still have a long way to go
- Strong exploit mitigations
Despite these drawbacks, desktop GNU/Linux distributions are great if you want to:
- Avoid telemetry that often comes with proprietary operating systems
- Maintain software freedom
- Have purpose built systems such as Whonix or Tails
Our website generally uses the term “Linux” to describe desktop GNU/Linux distributions. Other operating systems which also use the Linux kernel such as ChromeOS, Android, and Qubes OS are not discussed here.
Our Linux Recommendations :material-arrow-right:{ .md-button }
Release cycle
We highly recommend that you choose distributions which stay close to the stable upstream software releases, often referred to as rolling release distributions. This is because frozen release cycle distributions often don’t update package versions and fall behind on security updates.
For frozen distributions, package maintainers are expected to backport patches to fix vulnerabilities (Debian is one such example) rather than bump the software to the “next version” released by the upstream developer. Some security fixes do not receive a CVE (particularly less popular software) at all and therefore do not make it into the distribution with this patching model. As a result minor security fixes are sometimes held back until the next major release.
We don’t believe holding packages back and applying interim patches is a good idea, as it diverges from the way the developer might have intended the software to work. Richard Brown has a presentation about this:
Traditional vs Atomic updates
Traditionally, Linux distributions update by sequentially updating the desired packages. Traditional updates such as those used in Fedora, Arch Linux, and Debian based distributions can be less reliable if an error occurs while updating.
Atomic updating distributions apply updates in full or not at all. Typically, transactional update systems are also atomic.
A transactional update system creates a snapshot that is made before and after an update is applied. If an update fails at any time (perhaps due to a power failure), the update can be easily rolled back to a “last known good state”.
The Atomic update method is used for immutable distributions like Silverblue, Tumbleweed, and NixOS and can achieve reliability with this model. Adam Šamalík provided a presentation on how rpm-ostree works with Silverblue:
“Security-focused” distributions
There is often some confusion about “security-focused” distributions and “pentesting” distributions. A quick search for “the most secure Linux distribution” will often give results like Kali Linux, Black Arch, and Parrot OS. These distributions are offensive penetration testing distributions that bundle tools for testing other systems. They don’t include any “extra security” or defensive mitigations intended for regular use.
Arch-based distributions
Arch based distributions are not recommended for new users, regardless of the distribution. Arch does not have an distribution update mechanism for the underlying software choices. As a result the user of the system must stay aware with current trends and adopt technologies as they supersede older practices.
For a secure system, the user is also expected to have sufficient Linux knowledge to properly set up security for their system such as adopting a mandatory access control system, setting up kernel module blacklists, hardening boot parameters, manipulating sysctl parameters, and knowing what components they need such as Polkit.
Any user using the Arch User Repository (AUR), must be comfortable in auditing PKGBUILDs that they install from that service. AUR packages are user-produced content and are not vetted in any way and therefore are vulnerable to software supply chain attacks, which has in fact happened in the past. AUR should always be used sparingly and often there is a lot of bad advice on various pages which direct users to blindly use AUR helpers without sufficient warning. Similar warnings apply to using third party Personal Package Archives (PPAs) on Debian based distributions or Community Projects (COPR) on Fedora.
For advanced users, we only recommend Arch Linux, not any of its derivatives. We recommend against these two Arch derivatives specifically:
- Manjaro: This distribution holds packages back for 2 weeks to make sure that their own changes don’t break, not to make sure that upstream is stable. When AUR packages are used, they are often built against the latest libraries from Arch’s repositories.
- Garuda: They use Chaotic-AUR which automatically and blindly compiles packages from the AUR. There is no verification process to make sure that the AUR packages don’t suffer from supply chain attacks.
Linux-libre kernel and “Libre” distributions
We strongly recommend against using the Linux-libre kernel, since it removes security mitigations and suppresses kernel warnings about vulnerable microcode for ideological reasons.
--8<-- "includes/abbreviations.en.md"