CREST-Certified Web Application Penetration Testing
Independent web application testing delivered by CREST-certified ethical hackers. Our UK-based team identifies exploitable vulnerabilities across your web applications before attackers can use them.
- CREST-certified penetration testers
- Black Box, Grey Box, and White Box approaches available
- Clear reporting and remediation guidance
Trusted by organisations across regulated industries including finance, healthcare, enterprise software, and critical infrastructure.
Web Application Testing Services From OmniCyber
Our web application penetration testing services help organisations identify security weaknesses in their web applications before attackers can exploit them.
Using a structured testing methodology, our testers simulate real-world attack techniques to assess how well your web applications withstand attempts to compromise them, extract data, or gain unauthorised access.
We provide web application testing across the UK, supporting organisations that need assurance, compliance validation, or an independent assessment of their web application security posture.
When Do You Need Web Application Testing?
Most organisations with customer-facing or internal web applications eventually need to prove their security controls actually work. A professional web application test provides independent validation that your applications can withstand real-world attack techniques.
You may need web application testing services if you:
- Have developed or significantly updated a web application
- Are preparing for a compliance audit or security assessment
- Handle sensitive user data, financial information, or personal records online
- Modified authentication, added features, and integrated third-party services.
- Need an independent security testing provider to review your application before launch
Whatever the driver, the goal is the same. You need testing carried out by certified ethical hackers, using realistic attack techniques, with results you can trust to make informed security decisions.
Web Application Testing Approaches
As with network penetration testing, web application testing can be conducted using different approaches depending on the level of access and information provided to the tester.
Authorised (Authenticated) Testing
Authenticated web application testing encompasses the full breadth of the application, including logged-in areas, back-end resources, and management interfaces. This approach is designed to detect vulnerabilities and identify weaknesses across all components that an internal user or attacker with credentials could access.
Standard (Unauthenticated) Testing
Standard web application testing focuses purely on what an unauthenticated attacker can access through a web browser. This approach allows testers to evaluate the application from an external, real-world perspective, using techniques consistent with those an experienced malicious adversary would deploy.
Grey Box Testing
Grey box testing sits between black and white box approaches. The tester is provided with partial information, such as user-level credentials or basic architecture details, to simulate an attacker who has obtained limited access. This is often the most cost-effective approach for comprehensive coverage.
White Box Testing
White box testing provides the tester with full access to application source code, architecture documentation, and infrastructure details. This enables a thorough, in-depth review of the codebase alongside manual testing, maximising vulnerability coverage and reducing the likelihood of missed issues.
Web Application Testing Methodology
As an experienced web application testing provider, OmniCyber follows a structured and transparent methodology aligned with the OWASP Testing Guide and recognised security testing standards. Our CREST-certified testers combine automated scanning with expert manual testing to identify vulnerabilities that automated tools alone would miss.
- Scoping and Reconnaissance: We define the scope of your web application test, mapping the application’s attack surface including all endpoints, authentication mechanisms, user roles, and third-party integrations. This ensures testing is targeted at the components that matter most.
- Authentication and Session Management Testing: Assessment of login mechanisms, password policies, multi-factor authentication, session token handling, and logout functionality to identify weaknesses that could allow account takeover or privilege escalation.
- Input Validation and Injection Testing: Manual and automated testing for injection vulnerabilities including SQL injection, Cross-Site Scripting (XSS), XML injection, and command injection across all user-supplied input fields.
- Access Control and Authorisation Testing: Verification that users can only access the data and functions they are authorised to use, including testing for Insecure Direct Object References (IDOR), horizontal and vertical privilege escalation, and broken access controls.
- Business Logic Testing: Manual assessment of application workflows to identify logical flaws that could allow attackers to bypass security controls, manipulate transactions, or abuse functionality in unintended ways.
- Risk-Based Reporting: All findings are prioritised by likelihood of exploitation and potential business impact, providing your team with clear, actionable guidance for remediation.
- Remediation Support: Clear remediation guidance is provided for every vulnerability identified, with optional retesting available to confirm that fixes have been applied effectively.
Our Web Application Testing Services
OmniCyber provides a full range of web application security testing services across the UK, helping organisations identify and address vulnerabilities before they can be exploited.
OWASP Top 10 Testing
Comprehensive testing aligned to the OWASP Top 10, covering the most critical and commonly exploited web application security risks including injection flaws, broken authentication, and security misconfigurations.
Injection Vulnerability Testing
Manual and automated testing for SQL injection, Cross-Site Scripting (XSS), command injection, LDAP injection, and XML-related vulnerabilities across all user-controlled input points in the application.
Authentication and Session Testing
Assessment of login mechanisms, password policies, session token generation, and logout functionality. Identifies weaknesses that could lead to account takeover, session hijacking, or credential theft.
Access Control and Authorisation Testing
Testing that users are restricted to the data and functionality they are authorised to access, including IDOR testing, horizontal and vertical privilege escalation, and broken access control scenarios.
API Security Testing
Security assessment of REST, SOAP, and GraphQL APIs underpinning your web application, including testing for authentication weaknesses, excessive data exposure, mass assignment, and insecure endpoints.
Business Logic Testing
Manual assessment of application workflows and transaction flows to identify logic flaws that automated tools cannot detect, including process bypass, transaction manipulation, and abuse of application functionality.
Cross-Site Scripting (XSS) Testing
Testing for reflected, stored, and DOM-based XSS vulnerabilities that could allow attackers to execute malicious scripts in users' browsers, steal session cookies, or redirect users to malicious sites.
Security Configuration Review
Review of web server, application framework, and content security policy configurations to identify misconfigurations, unnecessary exposed functionality, insecure HTTP headers, and information leakage that could assist an attacker.
Source Code Review
Where white box testing is in scope, a manual review of the application source code is conducted alongside dynamic testing to identify security flaws at the code level that would not be visible through external testing alone.
Testing Against the OWASP Top Ten
OmniCyber’s web application testing covers the OWASP Top 10, the globally recognised standard for critical web application security risks. Our testers assess your application against each category using manual techniques to ensure comprehensive coverage.
- Broken Access Control
- Injection
- Security Misconfiguration
- Authentication Failures
- Security Logging Failures
- Insecure Design
- Cryptographic Failures
- Vulnerable Components
- Software Integrity Failures
- Server-Side Request Forgery
Web Application Testing For Compliance frameworks
Many organisations require web application security testing to meet regulatory and compliance requirements. OmniCyber supports organisations preparing for or maintaining compliance with recognised security frameworks.
This includes:
- ISO 27001
- Cyber Essentials Plus
- PCI DSS
- NHS DSPT
- DORA
- GDPR security risk assessments
Our CREST-certified web application testing helps organisations validate that security controls are working effectively and provides evidence required for compliance and assurance purposes.
What Our Clients Say About Our Services
Organisations across multiple industries trust OmniCyber to deliver professional penetration testing and clear security insights.
“What stands out most is the feedback I hear after introducing others to OmniCyber. They consistently say the team are the best penetration testers they have worked with because they work with you, not just against your systems.”
Global Travel Company
Head of Security
“Your report is the most detailed and practical we have reviewed. The level of clarity and prioritisation made it easy to understand what needed attention.”
Healthcare Industry
DevOps Manager
“The work and interactions (with Louie Augarde in particular) were so impressive we wouldn’t even consider tendering elsewhere at this point.”
UK Registered Charity
IT Infrastructure Manager
What You Receive from a Web Application Test
A professional web application test should provide clear insight into how attackers could compromise your application and what actions should be taken to reduce risk.
- Clear evidence of exploitable vulnerabilities
- How attackers could gain access and escalate privileges
- What user data or sensitive information would be exposed
- Which security controls fail under real attack conditions
- What to fix first, prioritised by risk and business impact
- Clear reporting for both technical and non-technical stakeholders
These insights are delivered in a structured report that places vulnerabilities in context, allowing your organisation to prioritise remediation and make informed security decisions.