Web Application Penetration Testing

What is a web application penetration test?

A web application penetration test is a manual security assessment of a web-based application, anything from a customer portal or SaaS product to an internal business system accessed through a browser. A tester works through the application the way an attacker would, looking for vulnerabilities that could be used to access data, manipulate functionality, or compromise the accounts of users or administrators.

The key distinction is the manual testing. Automated scanners can find known issues quickly, but they miss logic flaws, broken access controls and multi-step vulnerabilities. A penetration test combines tooling with hands-on testing to find what scanners leave behind.

What we test

Testing follows the OWASP Web Security Testing Guide (WSTG). Coverage includes:

• Authentication and session management: bypass mechanisms, session expiration, password reset abuse, and multi-factor authentication implementation.
• Access controls: unauthorised data access, cross-user record visibility, admin function restrictions, and API endpoint enforcement.
• Injection vulnerabilities: SQL injection, command injection, and backend system interference.
• Cross-site scripting (XSS): malicious script injection executing in user browsers and stealing session tokens.
• Security misconfigurations: default settings, unnecessary features, revealing error messages, and missing security headers.
• Business logic flaws: checkout process manipulation, price alteration, and access to features before payment.
• Sensitive data exposure: handling of personal information, credentials, and payment data in transit and in logs.

Who needs a web application penetration test?

• Compliance requirements: ISO 27001 expects application security assessment, PCI DSS mandates testing for systems handling cardholder data, and SOC 2 auditors typically require evidence of application security testing.
• Proactive testing: businesses test after building or updating an application, before it goes to production or in front of customers.

What the process looks like

A scoping call establishes how the application works and where to focus. Most work uses a grey-box approach, with user accounts and architectural context provided up front.

Testing usually spans two to five days depending on the size and complexity of the application, conducted in a test environment or at a coordinated time in production.

The report includes a management summary and a technical section for developers, with severity-rated findings and clear remediation guidance. Post-delivery support includes a walkthrough with your team and help with remediation questions.

Retesting

After you have addressed the findings, we offer a retest to confirm the issues are resolved, which is useful evidence for customers, auditors or insurers.