Why Linux Is the Most Secure Choice
for Your Business Web Server

First, the honest caveat

Anyone who tells you Linux is completely secure is either selling something or hasn't been paying attention. The Linux kernel accumulated 3,108 publicly documented vulnerabilities (CVEs) in 2024 alone — a 79% increase over 2023. ^[1] Kaspersky's data shows the number of Linux users encountering active exploits increased more than 50% in the first half of 2025 compared to the same period in 2024. ^[2]

Linux is not a security guarantee. It is, however, a better starting point than the alternatives for running a business web server — and the reasons why are worth understanding, because they inform what good hosting management actually looks like.

The CVE paradox: more vulnerabilities reported ≠ less secure

One of the most commonly misunderstood things in computing security is what a high CVE count actually means. A CVE — Common Vulnerability and Exposure — is a publicly documented security issue. The number of CVEs assigned to a piece of software is not a straightforward measure of how dangerous it is. It's partly a measure of how transparent its developers are.

In early 2024, the Linux kernel development team became a CVE Numbering Authority — meaning they gained the ability to formally assign CVE identifiers to their own security fixes. The immediate result was that thousands of issues that had previously been fixed quietly and undocumented were now being assigned public CVE numbers. The jump in Linux CVE counts in 2024–25 reflects improved transparency, not a sudden deterioration in code quality. ^[1]

Compare this to closed-source systems. Microsoft patches Windows vulnerabilities regularly — but not every fix gets its own public CVE assignment. Security issues can be quietly resolved in cumulative updates without any public vulnerability record. This makes direct CVE comparisons between Linux and Windows misleading. The OS with more public CVEs may simply be the one that's more forthcoming about what it fixes. ^[3]

So why does Linux account for only 1.3% of malware detections?

Despite running the majority of the world's internet infrastructure, Windows accounts for approximately 87% of global malware detections in 2025, macOS for 13%, and Linux for just 1.3% — even though Linux powers vastly more critical infrastructure than either. ^[4]

Several structural reasons explain this gap:

The privilege model. Linux was designed from the beginning as a multi-user system where no ordinary process has unrestricted access to the system. Programs run with the minimum privileges they need — a principle called least-privilege access. On a properly configured Linux server, a compromised web application cannot, by itself, rewrite system files, install software, or access other users' data. It's contained. On Windows, the traditional model gave applications much broader default access, which is why malware that infiltrates one application can so easily spread system-wide.

Package management. On Linux, software is installed through centralised package managers (apt, dnf, yum) that pull from cryptographically signed repositories maintained by the distribution team. Every package is verified before installation. This is completely unlike the Windows model of downloading executables from arbitrary websites and running them — a model that is responsible for an enormous proportion of Windows malware infections. ^[3]

Attack surface by design. A freshly installed Linux server runs almost nothing by default. You add only what you need: a web server, a database, a mail server, PHP. Everything else is off. A freshly installed Windows Server, by contrast, starts with a much larger default footprint — more services running, more ports potentially open, more attack surface before you've done any hardening.

Open-source auditability. Every line of Linux kernel code is publicly visible. Security researchers, academics, government agencies, and private companies all examine it continuously. When a vulnerability is found, it's typically patched within hours and the fix is publicly documented. This is a fundamentally different security model from closed-source software, where you're trusting the vendor's internal security process and have no way to verify what's actually in the code you're running.

Target economics. Malware is written to make money. Windows dominates the desktop — 72% of global desktop market share as of early 2026. ^[3] Writing malware that targets desktop Windows users is simply more profitable than writing malware for Linux servers, because there are more Windows desktop targets and the exploitation paths for average users are well-established. Linux servers are a harder target that requires more specialised knowledge to attack — which raises the cost and reduces the return for most attackers.

What Linux servers get attacked with — and how

Linux is not left alone by attackers. Understanding how Linux servers are actually compromised is useful context for anyone who manages one — or who has someone managing one on their behalf.

The most common attack vectors, according to current threat intelligence:

• Webshells (49.6% of Linux malware exploits) — attackers compromise a vulnerable web application (often a CMS plugin, an outdated PHP application, or a misconfigured file upload handler) and install a small PHP or Python script that gives them persistent remote access to the server. ^[4] This is why application-level security matters as much as OS-level security.
• SSH brute force — automated tools try millions of username and password combinations against the SSH port (port 22) of any publicly accessible server. Servers with weak or default passwords, or with SSH exposed on the default port, are at high risk. Proper SSH hardening — key-based authentication, non-standard port, fail2ban — largely eliminates this attack vector.
• Unpatched kernel vulnerabilities — the most commonly exploited Linux kernel CVEs in 2024–25 include CVE-2022-0847 ("Dirty Pipe"), a privilege escalation flaw that allows attackers to overwrite read-only files, and several Netfilter subsystem vulnerabilities. ^[5] The key word is unpatched. All of these have fixes available. A server that isn't kept up to date is a server that's vulnerable to attacks that have been publicly documented for years.
• Cryptominers and botnets — compromised Linux servers are frequently recruited into botnets or used to mine cryptocurrency, often without the owner noticing for weeks. The Mirai botnet family, which primarily targets Linux-based servers and IoT devices, remains one of the most prevalent malware families detected globally.

Notice what's not on that list: viruses spreading through email attachments, users clicking malicious links, drive-by downloads from compromised websites. Those are overwhelmingly Windows desktop attack vectors. Linux servers have a different threat model — and defending against it requires different disciplines.

What proper Linux server hardening actually looks like

A default Linux server installation is more secure than a default Windows Server installation, but "more secure than the alternative" is not a security posture. Proper hardening is active, ongoing work. Here's what it involves in practice:

• Firewall configuration (UFW/nftables/CSF) — only the specific ports required for your application are open. Everything else is blocked by default. Most servers need ports 80 (HTTP), 443 (HTTPS), and a non-standard SSH port. Nothing else.
• SSH hardening — root login disabled, password authentication disabled entirely in favour of SSH key pairs, fail2ban installed to automatically block repeated failed authentication attempts, SSH moved off port 22.
• Automatic security updates — unattended-upgrades configured to automatically apply security patches for the OS and installed packages. Critical kernel patches should be applied promptly; the Dirty Pipe vulnerability was publicly disclosed in February 2022 and patches were available the same day, yet it remains one of the most exploited Linux vulnerabilities in 2025 — entirely because servers were never updated.
• Mandatory access control (AppArmor/SELinux) — these kernel-level security modules confine individual programs to only the files and resources they legitimately need. A compromised web server process can't access your database credentials or your SSH keys even if an attacker gains control of it.
• Intrusion detection and log monitoring — tools like OSSEC or Wazuh monitor system logs in real time for unusual patterns: unexpected login attempts, new user accounts being created, files being modified in unexpected locations, processes running that shouldn't be.
• Principle of least privilege throughout — the web server runs as a non-root user. The database runs as a non-root user. The PHP application has read access to what it needs and write access to nothing more. Each service is isolated from every other service.
• Regular security audits — tools like Lynis provide automated security auditing of a Linux system, scoring it against established hardening benchmarks and flagging specific configuration gaps to address.

Why shared hosting undermines most of this

Most cheap web hosting puts your website on a server alongside potentially hundreds of other customers' websites. That server runs Linux, but the hardening decisions are made by the hosting provider and applied uniformly across all customers. You have no control over the firewall rules, no ability to configure AppArmor policies for your application, no say in which PHP version runs or how it's configured, and no visibility into what the other sites on the same machine are doing.

If one of those other sites gets compromised through a vulnerable plugin, that webshell is now on your server. If the hosting provider's shared configuration has a weakness, every site on that machine shares the exposure. This is the dirty secret of shared hosting: you're only as secure as the weakest site on your machine, and you have no idea who that is.

A VPS (Virtual Private Server) gives you your own isolated Linux environment with root access, where hardening decisions can be made specifically for your application and threat model. That's what I set up and manage for clients — a properly hardened, properly monitored Debian or Ubuntu server configured for exactly what's running on it, with nothing else. Not a shared environment. Not a generic template.

The honest summary

Linux is more secure than Windows as a web server platform for reasons that are structural and real: the privilege model, the package management system, the open-source auditability, and the minimal-by-default footprint. But "Linux" is not a security strategy. A poorly administered Linux server — unpatched, default SSH configuration, weak application code, no monitoring — will be compromised. Probably faster than you'd expect, because automated scanning tools probe every internet-facing IP address continuously.

The platform matters. The administration of the platform matters more.

Related reading: How a VPS lets you run your own secure and private server · Why most of the web runs on a LAMP stack · The real dangers of WordPress and too many plugins