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There is already a very indepth technical blog explaning the various security weaknesses of Linux by Madaidan, Whonix’s Security Researcher. This page will attempt to address some of the questions commonly raised in reaction to his blog post."><meta property="og:type" content="article"><meta property="og:url" content="https://privsec.dev/os/linux-insecurities/"><meta property="article:section" content="os"><meta name=twitter:card content="summary"><meta name=twitter:title content="Linux Insecurities"><meta name=twitter:description content="There is a common misconception among privacy communities that Linux is one of the more secure operating systems, either because it is open source or because it is widely used in the cloud. This is however, a far cry from reality.
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There is already a very indepth technical blog explaning the various security weaknesses of Linux by Madaidan, Whonix’s Security Researcher. This page will attempt to address some of the questions commonly raised in reaction to his blog post."><script type=application/ld+json>{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":2,"name":"Operating Systems","item":"https://privsec.dev/os/"},{"@type":"ListItem","position":3,"name":"Linux Insecurities","item":"https://privsec.dev/os/linux-insecurities/"}]}</script><script type=application/ld+json>{"@context":"https://schema.org","@type":"BlogPosting","headline":"Linux Insecurities","name":"Linux Insecurities","description":"There is a common misconception among privacy communities that Linux is one of the more secure operating systems, either because it is open source or because it is widely used in the cloud. This is however, a far cry from reality.\nThere is already a very indepth technical blog explaning the various security weaknesses of Linux by Madaidan, Whonix\u0026rsquo;s Security Researcher. This page will attempt to address some of the questions commonly raised in reaction to his blog post.","keywords":["operating system","security","linux"],"articleBody":"There is a common misconception among privacy communities that Linux is one of the more secure operating systems, either because it is open source or because it is widely used in the cloud. This is however, a far cry from reality.\nThere is already a very indepth technical blog explaning the various security weaknesses of Linux by Madaidan, Whonix’s Security Researcher. This page will attempt to address some of the questions commonly raised in reaction to his blog post. You can find the original article here.\nWhy is Linux used on servers if it is so insecure? On servers, while most of the problems referenced in the article still exists, they are somewhat less problematic.\nOn Desktop Linux, GUI applications run under your user, and thus have access to all of your files in /home. This is in contrast to how system daemons typically run on servers, where they have their own group and user. For example, NGINX will run under nginx:nginx on Red Hat distributions, or www-data:www-data on Debian based ones. Discreationary Access Control does help with filesystem access control for server processes, but is useless for desktop applications.\nAnother thing to keep in mind is that Mandatory Access Control is also somewhat effective on servers, as commonly run system daemons are confined. In contrast, on desktop, there is virtually no AppArmor profile to confine even regularly used apps like Chrome or Firefox, let alone less common ones. On SELinux systems, these apps run in the UNCONFINED SELinux domain.\nLinux servers are lighter than Desktop Linux systems by order of magnitude, without hundreds of packages and dozens of system daemons running like X11, audio servers, printing stack, and so on. Thus, the attack surface is much smaller.\nLinux Hardening Myths There is a common claim in response to Madaidan that Linux is only insecure by default, and that an experience user can make it the most secure operating system out there, surpassing the likes of macOS or ChromeOS. Unfortunately, this is wishful thinking. There is no amount of hardening that one can reasonably apply as a user to fix up the inherent issues with Linux.\nLack of verified boot macOS, ChromeOS, and Android have a clear distinction between the system and user installed application. In over simplified terms, the system volume is signed by the OS vendor, and the firmware and boot loader works to make sure that said volume has the authorized signature. 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Regardless of which application you install or how you install them, they have to play by the rules of an untrusted SELinux domain.\nOn Linux, it is quite the opposite.\n","wordCount":"589","inLanguage":"en","datePublished":"0001-01-01T00:00:00Z","dateModified":"0001-01-01T00:00:00Z","author":{"@type":"Person","name":"Tommy"},"mainEntityOfPage":{"@type":"WebPage","@id":"https://privsec.dev/os/linux-insecurities/"},"publisher":{"@type":"Organization","name":"PrivSec.dev","logo":{"@type":"ImageObject","url":"https://privsec.dev/%3Clink%20/%20abs%20url%3E"}}}</script></head><body class=dark id=top><script>localStorage.getItem("pref-theme")==="light"&&document.body.classList.remove("dark")</script><header class=header><nav class=nav><div class=logo><a href=https://privsec.dev accesskey=h title="PrivSec.dev (Alt + H)">PrivSec.dev</a><div class=logo-switches><button id=theme-toggle accesskey=t title="(Alt + T)"><svg id="moon" xmlns="http://www.w3.org/2000/svg" width="24" height="18" viewBox="0 0 24 24" fill="none" stroke="currentcolor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M21 12.79A9 9 0 1111.21 3 7 7 0 0021 12.79z"/></svg><svg id="sun" xmlns="http://www.w3.org/2000/svg" width="24" height="18" viewBox="0 0 24 24" fill="none" stroke="currentcolor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="5"/><line x1="12" y1="1" x2="12" y2="3"/><line x1="12" y1="21" x2="12" y2="23"/><line x1="4.22" y1="4.22" x2="5.64" y2="5.64"/><line x1="18.36" y1="18.36" x2="19.78" y2="19.78"/><line x1="1" y1="12" x2="3" y2="12"/><line x1="21" y1="12" x2="23" y2="12"/><line x1="4.22" y1="19.78" x2="5.64" y2="18.36"/><line x1="18.36" y1="5.64" x2="19.78" y2="4.22"/></svg></button></div></div><ul id=menu><li><a href=https://privsec.dev/knowledge/ title="Knowledge Base"><span>Knowledge Base</span></a></li><li><a href=https://privsec.dev/os/ title="Operating Systems"><span>Operating Systems</span></a></li><li><a href=https://privsec.dev/apps/ title=Applications><span>Applications</span></a></li><li><a href=https://privsec.dev/providers/ title=Providers><span>Providers</span></a></li></ul></nav></header><main class=main><article class=post-single><header class=post-header><div class=breadcrumbs><a href=https://privsec.dev>Home</a> » <a href=https://privsec.dev/os/>Operating Systems</a></div><h1 class=post-title>Linux Insecurities</h1><div class=post-meta>3 min · 589 words · Tommy | <a href=https://github.com/PrivSec-dev/privsec.dev/blob/main/content/os/Linux%20Insecurities.md rel="noopener noreferrer" target=_blank>Suggest Changes</a></div></header><div class=toc><details><summary accesskey=c title="(Alt + C)"><span class=details>Table of Contents</span></summary><div class=inner><ul><li><a href=#why-is-linux-used-on-servers-if-it-is-so-insecure aria-label="Why is Linux used on servers if it is so insecure?">Why is Linux used on servers if it is so insecure?</a></li><li><a href=#linux-hardening-myths aria-label="Linux Hardening Myths">Linux Hardening Myths</a><ul><li><a href=#lack-of-verified-boot aria-label="Lack of verified boot">Lack of verified boot</a></li><li><a href=#lack-of-application-sandboxing aria-label="Lack of application sandboxing">Lack of application sandboxing</a></li></ul></li></ul></div></details></div><div class=post-content><p>There is a common misconception among privacy communities that Linux is one of the more secure operating systems, either because it is open source or because it is widely used in the cloud. This is however, a far cry from reality.</p><p>There is already a very indepth technical blog explaning the various security weaknesses of Linux by Madaidan, <a href=https://www.whonix.org/>Whonix</a>’s Security Researcher. This page will attempt to address some of the questions commonly raised in reaction to his blog post. You can find the original article <a href=https://madaidans-insecurities.github.io/linux.html>here</a>.</p><h2 id=why-is-linux-used-on-servers-if-it-is-so-insecure>Why is Linux used on servers if it is so insecure?<a hidden class=anchor aria-hidden=true href=#why-is-linux-used-on-servers-if-it-is-so-insecure>#</a></h2><p>On servers, while most of the problems referenced in the article still exists, they are somewhat less problematic.</p><p>On Desktop Linux, GUI applications run under your user, and thus have access to all of your files in <code>/home</code>. This is in contrast to how system daemons typically run on servers, where they have their own group and user. For example, NGINX will run under <code>nginx:nginx</code> on Red Hat distributions, or <code>www-data:www-data</code> on Debian based ones. Discreationary Access Control does help with filesystem access control for server processes, but is useless for desktop applications.</p><p>Another thing to keep in mind is that Mandatory Access Control is also somewhat effective on servers, as commonly run system daemons are confined. In contrast, on desktop, there is virtually no AppArmor profile to confine even regularly used apps like Chrome or Firefox, let alone less common ones. On SELinux systems, these apps run in the UNCONFINED SELinux domain.</p><p>Linux servers are lighter than Desktop Linux systems by order of magnitude, without hundreds of packages and dozens of system daemons running like X11, audio servers, printing stack, and so on. Thus, the attack surface is much smaller.</p><h2 id=linux-hardening-myths>Linux Hardening Myths<a hidden class=anchor aria-hidden=true href=#linux-hardening-myths>#</a></h2><p>There is a common claim in response to Madaidan that Linux is only insecure by default, and that an experience user can make it the most secure operating system out there, surpassing the likes of macOS or ChromeOS. Unfortunately, this is wishful thinking. There is no amount of hardening that one can reasonably apply as a user to fix up the inherent issues with Linux.</p><h3 id=lack-of-verified-boot>Lack of verified boot<a hidden class=anchor aria-hidden=true href=#lack-of-verified-boot>#</a></h3><p>macOS, ChromeOS, and Android have a clear distinction between the system and user installed application. In over simplified terms, the system volume is signed by the OS vendor, and the firmware and boot loader works to make sure that said volume has the authorized signature. The operating system itself is immutable, and nothing the user does will need or be allowed to tamper with the system volume.</p><p>On Linux, there is no such clear distinction between the system and user installed applications. Linux distributions are a bunch of packages put together to make a system that works, and thus every package is treated as part of said system. The end result is that binaries, regardless of whether they are vital for the system to function or just an extra application, are thrown into the same directories as each other (namely <code>/usr/bin</code> and <code>/usr/local/bin</code>). This makes it impossible for an end user to setup a verification mechanism to verify the integrity of “the system”, as said “system” is not clearly defined in the first place.</p><h3 id=lack-of-application-sandboxing>Lack of application sandboxing<a hidden class=anchor aria-hidden=true href=#lack-of-application-sandboxing>#</a></h3><p>Operating systems like Android and ChromeOS have full system mandatory access control, every process from the init process is strictly confined. Regardless of which application you install or how you install them, they have to play by the rules of an untrusted SELinux domain.</p><p>On Linux, it is quite the opposite.</p></div><footer class=post-footer><ul class=post-tags><li><a href=https://privsec.dev/tags/operating-system/>operating system</a></li><li><a href=https://privsec.dev/tags/security/>security</a></li><li><a href=https://privsec.dev/tags/linux/>linux</a></li></ul><nav class=paginav><a class=prev href=https://privsec.dev/os/docker-and-oci-hardening/><span class=title>« Prev</span><br><span>Docker and OCI Hardening</span></a>
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