Do you need API documentation?

It helps considerably. With a specification or collection we cover endpoints systematically; without one we discover what we can and state the coverage limitation.

What is the most common serious finding?

Broken object-level authorisation — an endpoint that returns another customer's record when the identifier is changed. We test that across every role and tenant we are given.

How does a api security testing engagement start?

With a short discovery conversation and a written view of scope, risk and the decisions to be made. That view is useful to you whether or not the work continues.

How is a api security testing engagement priced?

Scope and, where relevant, rules of engagement are agreed in writing before any work begins, and the engagement is a fixed fee for that scope or phased with a cost envelope per phase — so you know the cost and the boundaries up front. Larger pieces of work are broken into phases with findings delivered early rather than a single invoice at the end.

Cybersecurity · Secure

API Security Testing

We test APIs against the failures that dominate real incidents: broken object-level authorisation, weak token handling, mass assignment and missing rate limits. Working from a specification or collection where one exists, we cover endpoints systematically and attempt to reach data and functions belonging to other users, tenants and organisations. Each finding is reported with the request that demonstrates it, the data it exposes and the fix that closes it. Because new endpoints often ship faster than they are reviewed, we also note where the pattern, not just the single endpoint, needs attention.

In short

API security testing examines authentication, authorisation, input handling and rate controls across your interfaces. It focuses on the authorisation and data-access failures that dominate real API incidents rather than only surface-level input flaws.

Start a conversation

What we do

The work inside api security testing.

Authentication and token handling

We test how tokens are issued, how long they last, whether their scope is enforced, and how keys are managed. We look for tokens that do not expire, scopes that are ignored once a token is accepted, and keys that grant more than intended. The result shows whether a leaked or stale credential would still open the door.

Object-level authorisation

We attempt to access records belonging to other users, tenants and organisations by altering identifiers in requests. This broken object-level authorisation is the single most common serious API finding, and we test it across every role and tenant we are given. Where an endpoint returns another party's data, we document exactly which identifier and which role reaches it.

Input validation and mass assignment

We test payload handling, type confusion and fields the client should not be able to set. Mass assignment lets a caller write attributes such as role or account status that were never meant to be exposed. We identify which fields are over-trusted and what elevating or tampering with them achieves.

Rate limiting and abuse

We test resistance to enumeration, brute force and volumetric abuse against the endpoints where it matters most, such as login, search and resource creation. Missing limits let an attacker guess credentials, harvest data or drive up cost. We report where throttling is absent and what an automated client could extract before anyone noticed.

What you receive

Deliverables, in writing.

Documented output your teams keep and can act on without us in the room.

Endpoint inventory with tested coverage
Authorisation findings across users and tenants
Input handling and mass assignment findings
Rate limiting and abuse assessment with remediation

When this work helps

You may be facing this.

APIs are exposed to partners or mobile clients
Multi-tenant data is served through shared endpoints
New endpoints ship faster than they are reviewed

How an engagement runs

Discover, assess, design, deliver.

01
Discover
Understand what matters most, the obligations in play, and what the organisation is genuinely trying to protect. We agree scope and rules of engagement in writing here, so testing is bounded and authorised before it begins.
02
Assess
Test and review the systems in scope, and establish real exposure rather than theoretical risk. We gather evidence for every finding, so severity reflects what we demonstrated rather than what is merely conceivable.
03
Design
Prioritise remediation, control improvements, and architecture changes against risk and effort. We sequence the work so the exposures that matter most are closed first, within what the team can realistically do.
04
Deliver
Support remediation, retest what was fixed, and help the practice hold as the environment changes. We confirm fixes actually closed the issue, rather than taking remediation on trust.

Where we work

Delhi, India — and wherever the work is.

Fidova delivers cybersecurity consulting and technical assurance from Delhi, India, and works with clients internationally; testing and review are performed remotely against your environments, with on-site work arranged when scope requires it.

Engagements run in English, are scheduled around your time zone, and can be delivered remotely end to end, with on-site time planned where a phase genuinely benefits from being in the room.

Related services

Often needed alongside this.

Network Security Assessment

Network security assessment examines exposure, segmentation and internal attack paths across your network estate. It establishes both what is reachable from the internet and how far an attacker could move once they had a foothold inside.

Cloud Security Assessment

Cloud security assessment reviews identity, configuration, network and data exposure across your cloud accounts. It measures how the environment is actually configured against how it was meant to be, concentrating on the identity and exposure issues that cause most cloud incidents.

Infrastructure Security Audit

Infrastructure security audit reviews servers, endpoints, virtualisation and supporting services against a defensible baseline. It reports where the running estate has drifted from that baseline across patching, configuration, privileged access and backup protection, and what to do about it.

All cybersecurity services

Questions