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When I first started my career in IT, I used to hear about all these security measures that everyone insisted on implementing. But I would think to myself: This won’t happen to me. I was wrong. Like many others in the industry, I underestimated the risks of misconfigurations and overlooked vulnerabilities—until I faced a serious security incident that could have been avoided. That experience taught me that what you don’t do is just as important as what you do.
In this article, I’m going to walk you through some of the critical mistakes to avoid when managing your servers—common pitfalls that can leave your infrastructure exposed and vulnerable. We’ll focus on the risks you can prevent by following best practices, from avoiding multiple applications on a single server to closing unused ports, and more.
1. Don’t Host Multiple Applications on a Single Server
Why It’s a Risk:
Using a single server to host multiple applications is like putting all your eggs in one basket. If one application has a security flaw, attackers can gain access to the entire server, compromising all other applications hosted on it. Even if an attacker can only breach one application, they can quickly escalate their access to other applications and data on the same server. This can lead to a domino effect, turning a single vulnerability into a full-blown data breach.
What You Should Avoid:
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- Don’t mix critical and non-critical applications on the same server.
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- Avoid deploying applications with varying security levels (e.g., a public-facing website and an internal database) on the same server.
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- Don’t cut costs by consolidating too many applications into one environment—it’s a false economy that can lead to severe security repercussions.
Risk Scenarios:
Imagine an outdated plugin in a low-priority web application being exploited. The attacker gains a foothold, and from there, it’s a short leap to access the server’s root directory, potentially impacting your critical business applications. This mistake can result in data loss, service outages, and a damaged reputation.
2. Never Use FTP for File Transfers
Why It’s a Risk:
FTP (File Transfer Protocol) is an outdated protocol that sends your data, including sensitive credentials, in plain text. This makes it an easy target for sniffing attacks, where hackers intercept the data as it’s being transmitted. Additionally, FTP lacks robust authentication and encryption features, making it a security liability in any modern server environment.
What You Should Avoid:
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- Don’t use FTP for any file transfers—switch to SFTP or FTPS.
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- Never leave FTP enabled on your server if it’s not actively in use; it’s a common entry point for brute force attacks.
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- Don’t assume FTP is harmless just because it’s not regularly accessed—hackers specifically look for these types of low-hanging fruits.
Risk Scenarios:
A common attack involves hackers using automated tools to scan for open FTP ports. Once they find one, they can launch brute force attacks to gain access. If successful, they can intercept sensitive files or upload malicious scripts, turning your server into a botnet or launching point for further attacks within your network.
3. Avoid Leaving Unused Ports Open
Why It’s a Risk:
Every open port on your server is a potential gateway for attackers. Even if no service is running on that port, it can still be used for reconnaissance or as a pivot point. Cybercriminals frequently scan for open ports to identify potential vulnerabilities they can exploit. Unused ports are often overlooked, making them a popular target for attackers looking for an easy way in.
What You Should Avoid:
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- Don’t leave ports open unless they are actively in use.
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- Avoid keeping default ports open for critical services (e.g., port 22 for SSH) without additional security measures.
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- Don’t neglect to update your firewall rules as your server’s configuration changes.
Risk Scenarios:
An organization may leave an unused port open after a service migration. This “forgotten” port becomes an easy entry point for an attacker, allowing them to establish a foothold within the network. Once inside, they can perform lateral movements to access more sensitive areas of your infrastructure, often without detection.
4. Never Skip Regular Penetration Testing
Why It’s a Risk:
Failing to conduct regular penetration tests is like flying blind when it comes to security. Vulnerabilities can creep into your system unnoticed, whether due to unpatched software, misconfigurations, or changes in your environment. Without regular testing, these flaws can remain hidden until an attacker finds and exploits them.
What You Should Avoid:
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- Don’t rely solely on automated vulnerability scanners; they often miss complex vulnerabilities.
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- Avoid testing only during compliance audits—penetration testing should be a continuous part of your security strategy.
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- Don’t ignore or deprioritize findings from penetration tests; unaddressed vulnerabilities are ticking time bombs.
Risk Scenarios:
A company might conduct penetration testing only once a year for compliance purposes. During the interim, new vulnerabilities emerge, and the IT team unknowingly introduces misconfigurations. This leaves the company exposed to attacks, making it easy for an external threat actor to bypass defenses and gain access to critical systems.
5. Don’t Rely Solely on Default Security Settings
Why It’s a Risk:
Default settings are often well-known and documented, making them a favorite target for attackers. Many companies fail to change default configurations for services like databases, CMS platforms, or remote access tools, believing the defaults are “good enough.” However, these settings are typically designed for functionality rather than security, leaving critical gaps.
What You Should Avoid:
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- Never leave default usernames and passwords on your systems.
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- Don’t assume default settings are optimized for security; always review and customize configurations based on your environment.
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- Avoid using “one-size-fits-all” settings across all servers and applications—tailor configurations to each specific use case.
Risk Scenarios:
Imagine a server running with a default database configuration that allows remote connections. An attacker could leverage this to execute malicious SQL queries, extract sensitive data, or even corrupt the database. Such oversights can turn into high-severity incidents, often because default settings are seen as harmless.
6. Don’t Ignore Outdated Software and Patches
Why It’s a Risk:
Running outdated software is one of the most common security mistakes. Attackers constantly look for known vulnerabilities in software versions that haven’t been patched. A single unpatched vulnerability can give an attacker complete control over your server, compromising everything from the operating system to your web applications.
What You Should Avoid:
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- Never delay applying security patches, especially for critical services.
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- Don’t overlook dependencies; an outdated library can provide a backdoor even if the main application is up-to-date.
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- Avoid relying on “set and forget” patching strategies; regularly review your patch management process.
Risk Scenarios:
Consider a web server running an outdated version of a CMS platform with a known vulnerability. An attacker could exploit this flaw to upload a malicious script, deface your website, or escalate privileges. Even if your server has a firewall and other security measures, an unpatched application creates an exploitable weakness.
Conclusion
Managing servers involves more than just ensuring uptime—it’s about proactively eliminating potential vulnerabilities and minimizing risks. By avoiding these critical mistakes—hosting multiple applications on a single server, using insecure protocols like FTP, leaving unused ports open, skipping penetration tests, relying on default settings, and delaying patches—you build a stronger, more resilient IT environment. Avoiding these common pitfalls not only secures your infrastructure but also positions you as a strategic leader who prioritizes the long-term security of your organization.
Is your server environment optimized for security? Connect with our team for a comprehensive risk assessment to uncover and mitigate potential threats.
