What’s the difference between a penetration test and a vulnerability assessment?

A vulnerability assessment is an automated scan that identifies known security weaknesses but does not actively exploit them. A penetration test goes further by manually testing and exploiting vulnerabilities to assess their real-world impact and severity.

Will penetration testing disrupt my business operations?

Penetration testing is carefully planned to minimize disruptions through controlled testing methods, coordinated schedules, and optional testing in staging or development environments instead of production.

Do you provide retesting after vulnerabilities are fixed?

Yes. GRSee offers retesting services to verify that vulnerabilities have been properly remediated and security improvements are effective before findings are closed.

Can API penetration testing help secure mobile applications?

Yes. Mobile applications rely heavily on backend APIs for authentication, data processing, and transactions. API penetration testing helps identify weaknesses that could expose sensitive data or allow attackers to bypass controls.

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API Penetration Testing Services

Q: How often should penetration tests be conducted?

Penetration testing should be performed at least annually or after major system updates, infrastructure changes, or security incidents. High-risk industries may require more frequent testing.

Q: What types of API vulnerabilities do you test for?

We test for vulnerabilities including broken object level authorization (BOLA), broken authentication, excessive data exposure, mass assignment, injection flaws, insecure endpoints, rate-limit weaknesses, and business logic flaws affecting REST, GraphQL, and mobile APIs.

Q: Do you test both internal and external APIs?

Yes. GRSee assesses both public-facing APIs and internal APIs used between services, applications, or microservices to identify hidden attack paths and security control weaknesses.

Protect the backbone of your applications. We test APIs with a dedicated methodology for microservices, mobile backends and integrations, not as if they were web pages.

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Working with GRSee felt like working with an extension of our own team.Tomer Cohavi, VP Engineering, Snappy

APIs are not web apps. We do not test them like one.

APIs carry your most sensitive logic and data, and they are often the first thing an attacker targets. Unlike vendors who reuse a web app checklist, we apply a methodology built for APIs, aligned with OWASP.

Whether you are securing a mobile backend, third-party integrations or service-to-service traffic, we combine strategic automation with manual testing of authorization, object access and business logic across every endpoint.

Penetration testing, done properly.

Expert ethical hackersExperienced security professionals with deep expertise in offensive security.
Advanced hybrid testingStrategic automation for common issues, manual deep-dive testing for the hard-to-find ones.
Tailored to your environmentEvery test is customized, so results are accurate and relevant.
Actionable insightsA report with prioritized remediation steps your engineers can act on.
Fast turnaroundComprehensive results without long waits, so you can act quickly.
Testers you can talk toKickoff, status updates and a post-assessment review, with testers on hand to clarify findings.
Results on our platformTrack status, manage remediation and see analytics on findings in one place.
Fixed scope, fixed priceOne clear quote upfront. No change orders mid-test.

How an API pentest runs.

Scope, test, report, retest: agreed with your team before we start.

Scope

Scope and attack surface mappingWe inventory every endpoint, version, method and consumer, including internal APIs and older versions still in service.
Discovery and reconnaissanceUsing your specs, traffic and documentation, we map how the API trusts callers and where data flows.

Test

Automated and manual testingAutomated checks across the endpoint surface, then manual testing of object-level authorization, mass assignment, rate limits and injection.
Exploitation and attack simulationWe chain issues to prove real impact: reading another tenant's records, escalating roles, bypassing business rules.
Post-exploitation and risk analysisWe trace what each weakness exposes downstream, in mobile apps, partners and other services, and rank it by risk.

Report

Reporting and remediation guidanceFindings ranked by risk, with clear, prioritized remediation steps your engineers can act on.

Fix and keep going

RetestingOnce fixes are in, we retest to confirm each finding is closed.
PT as a ServiceFor ongoing protection, continuous penetration testing through our PTaaS program.

External or internal APIs?

External APIs

Public endpoints used by your apps, customers and partners.

The surface every attacker can reach.

Internal APIs

Service-to-service and microservice traffic inside your environment.

Often trusted by default, which creates hidden attack paths.

We assess both, so a weakness inside does not become a breach outside.

What API penetration testing does for your business.

Stop data exposureClose the gaps that return more data than a caller should see.
Enforce who can access whatFind broken object-level and function-level authorization before attackers do.
Secure your mobile backendYour app is only as safe as the API behind it.
Trust your integrationsPartner and third-party connections tested for unsafe data handling.
Meet compliance requirementsEvidence for PCI DSS, SOC 2, ISO 27001 and customer reviews.

Why teams choose GRSee for API penetration testing.

We were very happy with the results and believe GRSee did a very thorough job with the penetration test.Marc Rubbinaccio, Head of Cybersecurity and Compliance, Secureframe

A dedicated API methodologyBuilt for REST, GraphQL, microservices and mobile backends, aligned with OWASP.
Business logic, not just signaturesWe test how your API is supposed to behave, and where it does not.
Help through remediationWe work with your team to prioritize fixes and retest them.

Related services

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API pentest guides from our team.

All resources

API pentest questions, answered.

Still not sure? Bring your questions to a scoping call.

What types of API vulnerabilities do you test for?

Broken object-level authorization (BOLA), broken authentication, excessive data exposure, mass assignment, injection, rate-limit weaknesses, insecure endpoints and misconfigured access control, plus business logic flaws specific to REST, GraphQL and mobile APIs.

Do you test both internal and external APIs?

Yes. Public APIs and the internal APIs used between services. Internal APIs are often trusted by default, which can create hidden attack paths.

Can API testing help secure our mobile app?

Absolutely. Mobile apps rely on backend APIs for authentication, data and transactions. Testing that layer finds weaknesses that let attackers bypass controls even when the app itself looks secure.

What do we receive after the test?

A report with validated findings, severity ratings, technical evidence, business impact and step-by-step remediation, plus help prioritizing fixes and a retest.

How long does an API pentest take?

Typically 2 to 6 weeks, depending on the number of endpoints, their complexity and the integrations in scope.

How often should penetration tests be conducted?

At least annually, and after major system updates, infrastructure changes or security incidents. High-risk industries may need more frequent testing.

Will testing disrupt our operations?

Testing is planned to minimize disruption. We coordinate timing, use controlled methods, and can test staging or development environments instead of production if you prefer.

Do you retest after we fix the findings?

Yes. We retest to verify that vulnerabilities have been properly remediated before findings are closed.

Book your scoping call.

Pick a time that suits you. You leave with a scope and a fixed quote.

Testers you can talk to
A retest after you fix
Results on our platform

Local teams, your time zone

United States
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We work in your time zone and support you in multiple languages.

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