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What web application penetration testing is
Web application penetration testing simulates real-world attacks to show how an attacker could exploit vulnerabilities in your applications, APIs and authentication flows. Our testers combine automated scanning with deep manual testing to uncover issues that affect the confidentiality, integrity and availability of your data.
Findings are prioritised by business impact and paired with clear remediation guidance, so your development and security teams can close high-risk gaps quickly — and evidence that they are closed.
Why it matters
Web application security testing helps you find and fix vulnerabilities before they turn into costly breaches. Simulating real attack scenarios surfaces hidden risks, validates your security controls and strengthens application defences.
This proactive approach protects sensitive data, safeguards your brand, supports regulatory compliance such as ISO 27001 and PCI DSS, and builds long-term customer trust in your digital platforms. It matters most where web applications carry sensitive data across banking, fintech, healthcare, e-commerce and SaaS.
How we approach the test
We match the testing depth to your risk and to what you need to evidence:
- Black box — an external attacker with no prior knowledge, testing publicly accessible applications and portals.
- Grey box — limited internal knowledge to uncover authentication flaws, business-logic weaknesses and privilege-escalation risk.
- White box — full visibility of source code and architecture to detect hidden vulnerabilities and insecure coding patterns.
- Authenticated testing — logged-in user roles, session handling and access control to prevent privilege misuse.
How we deliver
Our testing follows a structured, risk-based method to identify vulnerabilities, validate exploitability and strengthen your application security posture.
Scoping and requirement analysis
We define the objectives, application scope, compliance needs and risk priorities, and agree the testing approach — black, grey or white box — so the work aligns with your security and business goals.
Reconnaissance and threat modelling
We map the application architecture, user roles, data flows and attack surface to design an effective, targeted penetration test rather than a generic scan.
Automated and manual assessment
We test in depth, combining automated tooling with expert manual analysis to find both technical and business-logic vulnerabilities that scanners miss.
Controlled exploitation and validation
We safely exploit confirmed vulnerabilities to prove real-world impact and measure your actual business risk exposure, not theoretical severity.
Reporting and remediation support
You receive detailed reports with severity ratings, technical evidence and practical remediation guidance for both engineers and leadership.
Retesting and verification
Once fixes are in place, we retest to confirm the remediation is effective and the protection holds.
What you receive
- Executive summary of the risks found and what they mean for the business
- Detailed technical report with a full vulnerability breakdown and evidence
- Risk severity classification to prioritise remediation decisions
- Proof-of-concept evidence demonstrating real-world impact
- Practical remediation recommendations for each vulnerability
- Compliance mapping to the standards and regulations that apply to you
- Retesting and validation report confirming resolved vulnerabilities
Indicative timeline
A typical web application test runs from about one to two weeks, depending on the number of applications, the number of user roles and the testing depth agreed.
Timelines vary with scope and readiness; we confirm a schedule after scoping.
Tested against ASVS, not a checklist we invented
We test to the OWASP Application Security Verification Standard (ASVS), which defines verification levels from opportunistic through to advanced across authentication, session management, access control, input validation, cryptography, error handling and business logic. Testing to a published standard means you can tell a customer or an auditor exactly what was verified and to what depth — and it makes two tests a year comparable to each other, which a bespoke checklist never is.
APIs are tested as a first-class target
REST and GraphQL endpoints are assessed against the OWASP API Security Top 10, including authorisation logic betweenaccounts. Broken object-level authorisation — where one authenticated user reads another user’s records by changing an identifier — is the single most common serious finding we report, and it is invisible to an unauthenticated scan because it looks like ordinary, well-formed traffic.
Why automated scanning alone keeps missing things
Scanners are good at known, pattern-matchable defects: missing headers, outdated components, injection in obvious parameters. They are poor at the class of bug that actually loses data — authorisation gaps, privilege escalation between roles, and business-logic flaws where a legitimate sequence of requests produces an illegitimate outcome. None of those carry a signature. That is why our testing is manual-led with tooling underneath, and why we insist on credentials for every role in scope.
Critical vulnerabilities we identify
Our testing surfaces the high-risk vulnerabilities that expose applications to data breaches, unauthorised access and operational disruption:
Injection attacks
SQL, command and code injection flaws that let attackers manipulate your databases and run malicious commands.
Cross-site scripting (XSS)
Flaws that let attackers inject malicious scripts, hijack user sessions and steal sensitive information.
Broken authentication and sessions
Authentication weaknesses, insecure session handling and credential exposure that grant unauthorised access.
Broken access control
Privilege-escalation and access-control flaws that let users act beyond their authorised permissions.
Security misconfigurations
Improper configurations, exposed directories, default credentials and server weaknesses across the environment.
Sensitive data exposure
Weak encryption, improper storage and insecure transmission that can leak confidential data.
Representative engagement
A digital platform needed independent assurance across its customer-facing web application and its APIs before a customer security review. We scoped the application and its user roles, ran automated and manual testing, exploited the confirmed findings to prove impact, rated them by business risk, and retested after remediation to confirm closure. Named client references are available under NDA on request.
Who leads your engagement
Your engagement is led by senior application security testers — who do the manual testing that scanners cannot. Every finding passes independent quality review before the report reaches you. We introduce your named lead on the first call.
Frequently asked questions
What is application security testing?
Application security testing (AST) finds and validates vulnerabilities in web and business applications — covering the OWASP Top 10, authentication, access control, business-logic flaws and API security.
What is the difference between application security testing and penetration testing?
Application security testing focuses on an application’s code and behaviour; penetration testing simulates a real attacker end-to-end. CyberSigma combines both — manual pentesting plus AST — for audit-ready assurance.
Who provides application security testing services in India?
CyberSigma is CERT-In empanelled and provides application security testing and web app penetration testing across web, mobile, API and cloud for BFSI, fintech and SaaS firms in India.
What does a web application penetration testing engagement include?
A web application penetration testing engagement runs in phases: scoping and threat modelling, automated and manual assessment, controlled exploitation to prove real impact, a detailed report with prioritised findings, and a retest once fixes are in place.
Which vulnerabilities does web application security testing find?
Testing covers the OWASP Top 10 and beyond — injection, cross-site scripting, broken authentication and session management, broken access control, security misconfigurations, sensitive data exposure, and the business-logic and API vulnerabilities that automated scanners miss.
How long does a web application security test take?
Most web application tests run one to three weeks from scoping to report, depending on the size and complexity of the application, the number of user roles, and the depth of testing required. A retest after remediation confirms the fixes hold.
Do you provide black box, grey box and white box testing?
Yes. Black box testing simulates an external attacker with no prior knowledge, grey box uses limited credentials or documentation to reach authenticated flows, and white box adds source code and architecture for the deepest coverage.
What is included in the web application security testing report?
You receive an executive summary, a detailed technical report with proof-of-concept evidence, severity and risk ratings, practical remediation guidance, compliance mapping, and a retest and validation report confirming resolved issues.
Is web application security testing required for compliance?
It supports ISO 27001, PCI DSS, SOC 2 and enterprise security reviews, and regular application testing is expected under most of these frameworks. It is also the fastest way to reduce real breach risk in customer-facing applications.
What application security testing services actually cover
“Application security testing” is sold as one thing and delivered as several. When you compare proposals, you are usually comparing different combinations of the following — and the gaps between them are where real risk survives an engagement.
- SAST — static analysis of source code. Finds injection patterns and unsafe APIs early, produces false positives, and cannot see anything that only exists at runtime.
- DAST — dynamic testing against the running application. Sees what an attacker sees, misses what sits behind authentication unless credentials are configured.
- Manual application penetration testing — a tester with credentials working through business logic, authorisation and workflow. This is where broken access control and privilege escalation are found; no scanner produces these.
- API testing — increasingly the majority of real attack surface, and routinely assumed rather than scoped. Ask explicitly whether APIs are in scope and how many endpoints.
- Retest — a finding is not closed until it has been retested. If retest is a separate purchase order, the engagement price is not the engagement cost.
A proposal that quotes a single figure without naming which of these are included, how many roles are tested, and whether APIs are covered is not comparable to one that does. Our testing is manual-led against the OWASP Top 10 and ASVS, with authenticated testing across every user role and retest to closure included, delivered by CERT-In empanelled testers.