Web Penetration Testing

During a pentesting engagement, testers attempt to exploit weaknesses in an application's design, functionality, or configuration. By doing so, they can gain access to sensitive data or perform other unauthorized actions. In addition to finding and exploiting vulnerabilities, pentesters also work to identify the underlying cause of the vulnerability. This information can then be used to fix the problem and prevent future attacks. Pentesting is an important part of keeping web applications secure, and it should be performed on a regular basis.

VULNERABILITIES

Web Application Vulnerabilities

D3Fbyte assesses custom-built and third-party web applications from an attacker's point of view to uncover weaknesses that expose data, accounts, workflows, and administrative functions.

Our testing covers OWASP Top 10-style risks as well as chained attack paths across authentication, session handling, APIs, business logic, file uploads, and third-party integrations.

Web Attack Surface
08 09 10 11 12 13 14 15 16 17 18 19
const session = readCookie(req.headers.cookie);
if (!session.mfaPassed) { return redirect("/verify"); }
const profileId = req.query.id;
const order = db.orders.find(profileId);
if (order.accountId !== session.accountId) { throw Forbidden; }
const returnUrl = req.body.next;
render("checkout", { coupon: req.query.code });
uploadImage(req.files.avatar);
fetchWebhook(returnUrl);
if (req.query.export === "csv") {
  streamOrders(req.user.tenantId);
}
Auth Flow
IDOR Check
XSS Sink
Upload Review
Session State
SSRF Link

  • Injection flaws

    SQL, NoSQL, command, template, and server-side injection reachable from attacker-controlled input.

  • Broken access control

    Missing authorization checks that allow IDOR, tenant escape, privilege escalation, or admin abuse.

  • Authentication and session weaknesses

    Login flow abuse, weak MFA enforcement, predictable resets, and insecure session lifecycle handling.

  • XSS and client-side abuse

    Stored or reflected payloads that expose sessions, tokens, workflows, or privileged browser actions.

  • SSRF and integration abuse

    User-influenced requests to internal services, metadata endpoints, webhooks, or trusted back-end integrations.

  • Insecure file upload and processing

    Upload validation gaps, parser abuse, content-type trust, and execution paths tied to user-supplied files.

  • Business logic flaws

    Workflow bypasses, pricing abuse, race conditions, and sequencing weaknesses attackers can chain.

  • Security misconfiguration

    Dangerous defaults, verbose errors, exposed admin surfaces, and trust assumptions across environments.

PROCESS

How We Execute Web Application Penetration Tests

Each engagement starts with scoping the application, roles, exposed functionality, authentication paths, user journeys, integrations, and any sensitive workflows that matter most to a real attacker. We enumerate reachable inputs, map trust boundaries, and focus effort on the parts of the application where a single weakness can lead to meaningful access or impact.


From there we manually test exploit paths across authentication, authorization, session handling, stored and reflected input, uploads, APIs, and business logic. Findings are validated for real exploitability and then delivered with proof, affected endpoints, severity context, and practical remediation guidance your team can act on quickly.

Attack Surface
GET /account?id=42
POST /login { email, password }
PUT /admin/users/42
POST /avatar/upload multipart/form-data
GET /api/orders/export?format=csv
const returnUrl = req.body.next;
if (user.role !== "admin") {
  throw Forbidden;
Exploit Paths
Login Surface
User Flows
API Layer
Uploads
Admin Routes
Access-control chain Validate object ownership, role enforcement, and route protection across user and admin actions.
XSS, SSRF, and file abuse Trace untrusted input through browser rendering, back-end fetches, file handlers, and export features.
Client Deliverables
Verified Issue Confirmed weakness, affected endpoint, attack prerequisites, and concrete business or technical impact.
Proof of Exploit Reproducible request flow, payload notes, screenshots where useful, and severity rationale.
Remediation Guidance Prioritized fixes, compensating controls, and retest-ready recommendations for engineering teams.
Have Question?

Frequently Asked Question About Web Penetration Testing

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What is web application penetration testing?

A web application penetration test is a type of ethical hacking engagement designed to assess the architecture, design and configuration of web applications. Assessments are conducted to identify cyber security risks that could lead to unauthorised access and/or data exposure.

Who performs a web application penetration test?

Redscan web application penetration testing is performed by a team of CREST CCT APP certified professionals that have a deep understanding of the latest tactics and techniques that adversaries use to compromise web applications.

What information is needed to scope a web app pen test?

The information needed to help scope a web application security test typically includes the number and types of web applications to be tested, number of static and dynamic pages, number of input fields and whether the test will be authenticated or unauthenticated (where login credentials are unknown/known)

What is the difference between web app testing and vulnerability scanning?

Web app pen testing focuses specifically on identifying security vulnerabilities in web applications while vulnerability scanning is an automated approach that aims to provide a broader overview of potential security risks, looking at aspects areas such as networks, servers, routers, mobile devices, websites and network applications. As a subset of vulnerability assessments, automated vulnerability scans are run via commercial scanner services or platforms on network infrastructure or application components.