Having a website today is like having a store that is open 24 hours a day: there is always someone watching, and not always with good intentions. That's why, if you want to keep your website secure and out of reach of attacks, performing a pentest (or penetration test) is one of the best decisions you can make.
Does it sound complicated? Don't worry. In this article, we explain what web pentesting is, why it's so important, and how you can use it to detect flaws before hackers do.
What is Web Pentesting?
Web pentesting (or penetration testing) is basically testing the security of your website before attackers do. How? By simulating a real attack to find vulnerabilities, configuration errors, or any weak points that could be exploited. It's like hiring someone who thinks like a hacker, but to help you close doors, not open them.
The idea is not only to detect potential flaws, but also to understand how serious they would be if someone actually exploited them. That's why this type of testing doesn't just scratch the surface: it goes beyond what an automatic scan gives you and combines tools with manual analysis.
In short, pentesting simulates real attacks, but in a controlled and secure environment, with the aim of discovering how vulnerable your site or application is. Everything is thoroughly reviewed: from the front-end that the user sees, to the back-end, databases, source code, and APIs that connect everything behind the scenes.
Unlike automatic scans, these tests are manual and much more detailed. They require cybersecurity expertise, knowledge of how web applications are built, and, above all, the ability to think like an attacker. It's not just about finding flaws, but understanding how serious they could be, how they would affect your system, and how exposed you really are.
How is it different from a vulnerability scan?
It's simple: a vulnerability scan tells you “there could be a problem here,” while a pentest goes one step further and shows you whether that problem can actually be exploited and what impact it would have. It's like the difference between a smoke alarm and a firefighter checking to see if a fire has already started.
What is web pentesting for and why should you do it?
If you're still wondering whether web pentesting is worth it, the short answer is: yes, very much so. But to give you a clearer idea, here's what it's really for and how it can help you protect your site, your business, and your customers' trust.
1. Strengthen your site's security
Having a website (especially if it's part of a business) involves handling sensitive data: user information, payments, access, emails, etc. It's not just about having antivirus software or a firewall; web security needs a more thorough review.
That's where pentesting comes in: by simulating real attacks, it detects flaws that you might be overlooking. And we're not just talking about technical errors, but vulnerabilities that can open the door to a real cyberattack. With a good pentest, you can close those gaps before someone takes advantage of them.
2. It helps you prevent attacks before they happen
When you know your weak points, it's much easier to protect them. Pentesting shows you, with real data and examples, where the risk lies and how to fix it. So instead of reacting after an attack, you can get ahead of it and prevent it at the root.
And yes, cyberattacks are becoming more common, even for small sites. Don't wait for something to go wrong to take action: better safe than sorry.
3. Build trust with your users and customers
Security not only protects your site, it also protects your reputation. When users know they are on a trustworthy site, they browse with greater peace of mind, leave their data without fear, and are more likely to return. Digital trust is key, and pentesting is a direct tool for strengthening it.
In addition, demonstrating that you take cybersecurity seriously speaks well of your brand or company, improves your image, and helps you build stronger relationships with your customers.
In short, web pentesting is a smart way to prevent scares. It's not about being paranoid, but about being proactive with the security of your project.
Read more: What is Pentesting in Cybersecurity?
Phases of Web Pentesting: Step by Step
For pentesting to be truly useful, it must follow a series of well-defined stages. Each one plays a key role in the process of evaluating your site's security, so it is important to be familiar with them and ensure that they are carried out correctly.
Below, we explain the main phases that must be followed to perform effective pentesting, without complications and with clear results.
1. Planning
Every good pentest begins with good planning. In this phase, the objectives of the test are defined, which parts of the site will be evaluated, and what the overall focus of the process will be.
Do you want to do a complete review? Or focus on specific areas such as authentication or APIs? This is the stage where all that is decided. It is also the perfect time to share any concerns you may have about potential vulnerabilities or critical areas of the system. Clear planning avoids surprises and ensures that the test focuses on what really matters.
2. Information Gathering
Before starting the tests, the pentester needs to have a thorough understanding of the environment they are going to analyze. This is especially true if they are someone outside your team.
In this phase, data such as the following is collected:
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IP addresses
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Technologies used (CMS, frameworks, plugins)
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Access points
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Server configuration
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General infrastructure
All this information is used to understand how your site is built and what types of techniques may be most effective in simulating a real attack.
3. Vulnerability Analysis and Scanning
Once you have the full picture, the technical part begins: detecting weak points. Here, tools are used to scan the site for known flaws, configuration errors, code breaches, or outdated components.
Although many tests can be automated, experienced pentesters also perform manual analyses to find more complex or system-specific flaws.
Some popular tools at this stage are:
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OWASP ZAP
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Nessus
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Nmap
The goal here is not only to find flaws, but to understand how they could be exploited by a real attacker.
4. Exploiting Vulnerabilities
With the weaknesses detected, it's time to see how far you can go with them. In this phase, the pentester attempts to exploit the flaws as a cybercriminal would, but in a controlled environment and with great care not to cause damage.
For example, if an SQL injection is detected, they test whether it is possible to access information from the database. Or if there is an XSS vulnerability, they attempt to execute a malicious script.
The purpose is not to break the site, but to demonstrate the real impact an attack would have and prioritize risks according to their severity.
5. Results Report
After completing the tests, it is time to document everything. The pentester must deliver a detailed report that includes:
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The vulnerabilities found
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How serious they are (classified by risk level)
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How they were exploited
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Evidence (screenshots, logs, examples)
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Clear recommendations for correcting each flaw
This report is key for your development or IT team to take effective and orderly action.
6. Correction and Final Review
With the report in hand, it's time to get to work. The next step is to apply the necessary corrections to close the security gaps. As far as possible, it is best to follow the pentester's recommendations, as they are tailored to the specific context of your site.
Once the corrections have been made, it is highly recommended to perform a new round of testing (retesting) to verify that the flaws have actually been fixed and that no new problems have been introduced by accident.
Read more: Phases of Pentesting: How to secure your systems step by step?
How often should you perform web pentesting?
One of the most common questions when talking about web pentesting is: how often should pentesting be performed? And it makes perfect sense. Knowing when to repeat these tests can make the difference between preventing an attack and having to react too late.
The general recommendation from cybersecurity experts is to perform pentesting at least once a year. This frequency allows you to maintain regular control over the security of your site and ensure that no new vulnerabilities have appeared over time.
However, there are specific situations in which it is advisable to perform a new pentest, even if a year has not passed since the last one:
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If you changed your web infrastructure or added new features.
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If you made significant changes to the code.
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If you adopted new security policies.
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If you suffered (or suspect) a security incident.
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Before launching a new application or site into production.
In summary: it's not just about meeting a deadline, but knowing when your environment has changed enough to retest it.
Why is repeating pentesting (retesting) so important?
Every time you perform a pentest, you are one step ahead of cybercriminals. It's not about paranoia, it's about prevention. Benefits of performing these tests regularly.
1. It protects you against new (and old) threats
Cybersecurity is not static. Threats are constantly evolving, and what was secure yesterday could be a critical breach today. By performing pentesting regularly, you ensure that you identify weaknesses before someone else does. And not only that. It also helps you stay up to date with new cyberattack techniques.
2. Continuous improvement of your website
Pentesting is not just about plugging holes; it is also a tool for continuous improvement. With each analysis, you gain valuable information to optimize the security, performance, and structure of your site.
By correcting vulnerabilities and adjusting configurations, you are also strengthening the overall functioning of your website. So it's not just about preventing attacks, but about making your site more robust and stable over time.
3. Detect internal breaches (which are not always obvious)
We often think about external threats, but we mustn't forget internal risks. A well-done pentest can also reveal:
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Human errors that leave the system exposed
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Configuration flaws that allow unauthorized access
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Breaches that could be exploited from within the organization
With this information, you can reinforce policies, review access, and prevent problems before they escalate.
Read more: Types of Pentesting: Which one is right for your business?
Conclusion
Web pentesting is not something you do once and forget about. It is a practice that should be a constant part of your digital strategy. By applying it with the right frequency (and especially after making major changes to your site) you ensure that everything remains under control: no surprises, no breaches, no unnecessary risks.
Because let's be honest: preventing an attack will always be easier, faster, and cheaper than recovering from one. And we're not just talking about money, but also the trust of your users, your online reputation, and the stability of your business.
At TecnetOne, we have a team of certified ethical hackers who specialize in performing professional, ethical, and customized pentesting according to the needs of your site or application. We simulate real attacks in controlled environments to detect critical vulnerabilities before cybercriminals do.
So if you haven't done pentesting in the last year, or if you've made recent changes to your website, now is the perfect time to do so.
