Our application penetration testing services find and fix flaws in your web and mobile apps. This goes well beyond a simple vulnerability scan. We simulate real attacks to see how your apps hold up. We find weak spots early. Fixing them keeps your apps secure and reliable. It also keeps you in step with industry standards.
Attackers aim at your apps first. Your business now runs on those apps. Penetration testing finds and fixes flaws early. That helps you head off data breaches, unauthorized access, and other security incidents. Your apps may hold customer data, intellectual property, or your own business processes. Keeping them safe protects trust and keeps you in line with PCI-DSS, GDPR, and OWASP standards.
Our application penetration testing services follow one methodology applied to three surfaces. Web applications are tested against the OWASP Web Security Testing Guide and the OWASP Top 10: authentication, access control, injection, session handling, and business-logic abuse. APIs (REST, GraphQL, and SOAP) are tested against the OWASP API Security Top 10, with particular attention to broken object-level authorization, excessive data exposure, and unauthenticated endpoints that scanners never find. Mobile apps on iOS and Android are tested against the OWASP MASVS and MASTG, covering on-device storage, transport security, and the backend APIs the app talks to. Most engagements run gray box: we work with test credentials and documentation so the hours go to finding flaws, not rediscovering what you could have handed us on day one.
Not sure which fits? Black box vs. white box vs. gray box testing, explainedWeb application penetration testing takes a hard look at your web apps. The goal is to find weak spots before attackers do. We review your app code, its setup, and the infrastructure under it. You get a clear view of your real risks.
We check how your app handles user authentication and authorization. Done right, it keeps out anyone who should not get in.
We probe your input fields for flaws. These include SQL injection, cross-site scripting (XSS), and other injection attacks.
We review how your app handles user sessions. That covers safe cookie use and defense against session hijacking.
We check how your app sends and stores sensitive data. That includes your encryption practice and your defense against data leaks.
Our testers first gather facts about your web app. We look at how it is built and the tech it runs on. We also collect anything already public. This shapes a sharp attack plan.
Our experts pair automated tools with hands-on testing. Together they surface the flaws in your web app.
Next, our testers try to exploit the flaws they found. This shows what each flaw could really cost you. They may reach sensitive data, raise their own access rights, or slip past security controls.
You get a full report. It lists each flaw we found, what it could cost you, and how to fix it. We then help you rank the fixes and close them out.
Mobile application penetration testing finds security flaws in your mobile apps. We test against the OWASP Mobile Application Security Verification Standard (MASVS). This matters most for apps that hold sensitive data. It also matters for apps that open up key business tasks on a phone.
We review how your app is built. We hold the design against security best practice. That covers how it sends data and how it stores it.
We check how your app stores sensitive data on the device. That data should be encrypted and closed off to anyone else.
We confirm that your app signs users in safely and guards each session. That includes how it handles tokens and timeouts.
We read your source code for common security bugs. Think hardcoded secrets, unsafe API calls, and weak error handling.
We set the scope of the mobile application test with you. We target the areas that matter most under the OWASP MASVS guidelines.
We run deep security testing across every MASVS requirement. We look for unsafe data storage, weak session handling, and weak encryption.
We use dynamic testing, which probes the app while it runs. We also use static analysis, which reads the source code. Both surface security flaws.
You then get a detailed report with a MASVS compliance checklist. It shows where your app meets the standard and where it falls short. Each gap comes with a clear fix.
Application penetration testing finds flaws before attackers can use them. That shields your apps from cyber-attacks.
Show that your apps meet PCI-DSS, GDPR, and OWASP guidelines. Meeting them helps you avoid steep fines and legal trouble.
A safe app earns user trust. Trust is what keeps your name strong and your customers loyal.
Attackers probe your applications first. So our application penetration testing services cover the whole surface. We test the web apps your customers touch and the APIs behind them. We also test the authentication flows that link them. We probe single sign-on, session handling, and role limits the way a real attacker would.
We align testing to the OWASP Top 10. Injection, broken access control, and authentication failures are all in scope. Automated scanning gives us breadth. Senior testers then exploit by hand what the tools flag. That proves which weak spots an attacker could really reach in your setup.
You get findings ranked by real-world exploitability, not by raw severity scores. Each one comes with clear fix steps your developers can act on. You also get a report your auditors will accept. Some fixes belong in the infrastructure, not the code. When that happens, we say so and name the control that must change.
Security testing in 43 seconds:
Pair this work with our network penetration testing services to cover everything below the application layer. You can also browse the wider range of penetration testing services we offer. Or feed the results into an ongoing vulnerability management program, so issues stay closed. Talk to an Essendis penetration testing expert to scope your next application test.
Every finding in an Essendis application penetration testing report follows the same structure, so your developers can reproduce it and your auditor can trace it. Here is one representative finding, sanitized.
| Finding | APP-004: Broken object-level authorization on /api/v2/invoices/{id} |
| Severity | High (CVSS 8.1) — exploited, not theoretical |
| Impact | An authenticated customer could retrieve any other customer's invoices by incrementing the ID. 1,240 records reachable in testing. |
| Evidence | Request/response pair, screenshot, timestamped log reference |
| Remediation | Enforce ownership check server-side on every invoice read; add an integration test that asserts cross-tenant reads return 403. |
| Framework mapping | OWASP A01; PCI DSS 6.2.4; SOC 2 CC6.1; NIST SP 800-53 AC-3 |
| Retest status | Fixed — verified 14 days after delivery |
Broad market ranges in 2026 run roughly $6,000–$40,000+ for a web application or API test, driven by application size, user roles, and API surface, and roughly $8,000–$30,000 per platform for a mobile application. Those are industry ranges, not Essendis pricing: we quote a fixed fee after a short scoping call, bundle the retest, and tell you if a smaller test satisfies your requirement. Our guide to how much a penetration test costs explains every lever that moves the number.
Every web and API engagement tests each OWASP Top 10 (2021) category below by hand, not just by scanner. Your report maps every finding back to its category so auditors can see coverage at a glance.
| OWASP category | What we test | Covered |
|---|---|---|
| A01 Broken Access Control | IDOR, privilege escalation, role bypass, forced browsing | ✓ |
| A02 Cryptographic Failures | Weak TLS, sensitive data in transit and at rest, key handling | ✓ |
| A03 Injection | SQL, NoSQL, OS command, LDAP, and template injection; XSS | ✓ |
| A04 Insecure Design | Business-logic abuse, missing rate limits, workflow bypass | ✓ |
| A05 Security Misconfiguration | Default credentials, verbose errors, headers, cloud and framework settings | ✓ |
| A06 Vulnerable and Outdated Components | Library and framework versions, known CVEs, dependency exposure | ✓ |
| A07 Identification and Authentication Failures | Credential stuffing, MFA bypass, session fixation, weak password reset | ✓ |
| A08 Software and Data Integrity Failures | Insecure deserialization, unsigned updates, CI/CD trust assumptions | ✓ |
| A09 Security Logging and Monitoring Failures | Whether attacks we ran were logged, alerted, and attributable | ✓ |
| A10 Server-Side Request Forgery | Internal service reach, cloud metadata access, URL-fetch abuse | ✓ |
API engagements add the OWASP API Security Top 10; mobile engagements add the OWASP MASVS. See the full range of penetration testing services for network and cloud coverage.
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