Brittany MasloA designer’s role is to create a clear route that helps users move from entry to completion with minimal friction. A hacker looks at the same interface and searches for places where that journey can be broken, bypassed, or manipulated to make the system behave in ways it was never intended to.
Hackers map opportunities, not screens
At the beginning of an attack, a threat actor does not read the UI the way a regular user does. Instead, they build a map of opportunities. They look for data entry forms, registration and password recovery flows, and identify the roles available within the system, such as guest, user, manager, or administrator.
Another area of focus is the set of states that rarely appear in design mockups. For example, what happens if a password reset link has expired, if a user opens someone else’s invoice, or if a session expires in the middle of an action. Vulnerabilities are often found within these edge-case scenarios.
Where design decisions influence security
Designers are not responsible for every vulnerability. However, they can influence a product’s security through user flow logic long before the first line of code is written. A few common examples can be seen below:
- Excessively specific login error messages. If a system displays messages such as “this email does not exist” or “incorrect password,” it provides attackers with clues about whether an account exists in the database. A neutral message such as “invalid credentials” is a safer option.
- The same interface for different user roles. When managers and administrators see nearly identical screens but have different permissions, the boundaries between roles become less clear. These are exactly the kinds of areas attackers tend to investigate first.
- Share links, invite links, and magic links. If factors such as expiration periods, access revocation, and intended recipients are not carefully considered, these features can introduce weaknesses into the authorization logic.
What is a web application pentest and why designers should care
Now that it is clear how an attacker thinks, it becomes easier to understand what a web app pentest actually is. A web app pentest examines how the application would withstand the techniques used by an actual attacker. It involves testing user flows, roles, forms, authentication mechanisms, user accounts, file uploads, checkout processes, password reset functionality, and hidden administrative features.
If usability testing reveals where users become confused or frustrated, a pentest reveals where attackers may have an advantage. A penetration tester does not simply run automated scans against a website. Instead, they follow the same paths a real attacker would take, looking for opportunities to manipulate parameters, bypass controls, escalate privileges, or gain access to other users’ data.
The result is not a list of abstract vulnerabilities. It is a set of practical attack scenarios that demonstrate how an attack could unfold and what consequences it could have for both the product and the business.
What designers can do ahead of pentest
A designer does not need penetration testing expertise to contribute to product security. However, they can help surface potential issues much earlier, at the design stage, when fixing them is significantly less expensive.
A few practical steps include:
- Document roles and permissions directly within user flows instead of leaving them solely for development teams to define.
- Design not only the happy path but also edge cases, such as error states, account lockouts, expired links, and insufficient access permissions.
- Include states such as “access denied,” “session expired,” “link expired,” and “file rejected” rather than leaving them undefined.
- Avoid exposing unnecessary information in error messages.
- Carefully design the behavior of share links and invite links, including expiration periods, access restrictions, and revocation options.
- Ask security-focused questions during the design process: “What happens if a user attempts this action without the required permissions?”, “Can one role access another role’s data?”, or “What happens after logout?”
These practices do not replace the work of a security team. However, when designers consider potential misuse scenarios during the wireframing and prototyping stages, they can help reduce the number of logical flaws that may later be identified during a penetration test.
Taking these precautions can make a product more secure, but dedicated penetration testing remains essential. External security experts play an important role because they can identify weaknesses that may appear safe during the design phase but create serious risks during real-world attacks.
Cybersecurity companies, such asDatami Cybersecurity company, evaluate web applications from an attacker’s perspective. They follow user flows, test permissions, analyze business logic, and identify weaknesses in forms, roles, and system behavior under unusual conditions. This type of expertise is essential for uncovering subtle vulnerabilities and addressing them before they can be exploited.
Conclusion: Designers as part of product security
A web application pentest is not just a review of code. It is an assessment of how a product behaves when used by someone who is not following the rules. For this reason, designers also play a role in product security, as they shape user flows, roles, system states, error handling, and user expectations.
For a digital product team, a pentest should not be viewed as a final exam conducted after launch. It is a way to identify where the product could be used in unintended ways. The earlier design, product, and security teams begin speaking the same language, the fewer risks ultimately reach the end user.
