How well protected are your APIs?
APIs do the quiet work behind almost everything you run. They let your website, mobile app, cloud platform, internal systems, and third-party services talk to each other and share data.
That also makes them a target. Weak authentication, loose access controls, responses that reveal too much, or a sloppy configuration can all give an attacker a way in. We find those weaknesses before someone else does.
At Sunvak Boreal, we look at how your APIs handle authentication, authorisation, data, requests, and responses, and how they control access to your application’s functions. You won’t get a pile of maybes. You’ll get the risks that matter and practical advice your developers can use.
Not sure your APIs are properly protected? Talk to Sunvak Boreal about what you need tested.
What is API security testing?
It’s a controlled check for weaknesses in an API that an attacker could exploit.
APIs often give direct access to your application’s data and features. If an API doesn’t properly check who is asking, or what that person is allowed to do, it can hand over more than you ever intended.
Depending on your setup, we can look at authentication, authorisation, access controls, input validation, data exposure, rate limiting, token and session handling, configuration, error handling, business logic, endpoints, and object-level access controls. The exact areas depend on your API’s architecture, technology, features, and the scope we agree.
Why it matters
APIs tend to sit close to the important stuff: customer accounts, transactions, internal information, and third-party services. So a weakness in an API rarely stays inside the API.
Testing helps you find broken access controls, weak authentication, excessive data exposure, insecure endpoints, and token or rate-limiting problems. It also shows you how an attacker might move through your systems, so you can fix the riskiest things first and strengthen your controls.
The goal is simple: a clearer picture of how well your APIs are really protected.
What we test
Authentication. Is this request really coming from who it claims to be? We look at tokens, credentials, login mechanisms, token expiry, and related controls, hunting for ways someone could get in without permission.
Authorisation. Knowing who someone is doesn’t settle what they should be allowed to do. We check whether logged-in users can reach resources or functions beyond their permissions.
Object-level authorisation. APIs often use IDs to fetch records. If the API doesn’t check ownership, a user might see someone else’s data just by changing a value in a request. We test for exactly that.
Function-level authorisation. An ordinary user shouldn’t be able to use admin features. We check that the right endpoints and functions enforce the right permissions.
Input validation. APIs take in data with every request, and poor handling of it can create vulnerabilities. We test how your API deals with different kinds of input and whether the right protections are in place.
Sensitive data exposure. Some APIs return far more than the app needs. That’s a real privacy and security concern, especially with personal, financial, healthcare, or business data. We look at responses and endpoints for unnecessary exposure.
Tokens and sessions. We look at how tokens are created, validated, stored, and expired, and how access to them is controlled.
Rate limiting and abuse. Where it’s in scope, we check whether your API can be hammered with excessive or repeated requests.
Business logic. Some flaws aren’t technical bugs at all. They’re gaps in how a process was designed, and attackers can use legitimate functions in ways nobody planned for. We look for those.
Configuration. Security also depends on how your APIs are set up and exposed. We look for unnecessary exposure, weak settings, and information leaks.
How we work
1. Scope and planning. We start by learning about your API environment, technology, architecture, and goals. Then we agree what’s in scope: which APIs, endpoints, environments, accounts, and functions.
2. API discovery. We map the endpoints, features, authentication methods, parameters, request methods, and data flows within scope, so we know what an attacker would be looking at.
3. Security testing. We run controlled tests against the agreed APIs, using techniques that suit your architecture and goals. The OWASP API Security Top 10 is a useful reference for the most common risks, including broken object-level authorisation, broken authentication, unrestricted resource consumption, and security misconfiguration.
4. Validation. Where it makes sense, we confirm whether a finding is a real risk and how it could be exploited.
5. Risk prioritisation. We weigh potential impact, how easy it is to exploit, which functions are affected, and the surrounding environment, so your team knows where to start.
6. Reporting. For each issue, the report explains what it is, where we found it, why it matters, the potential impact, the technical details, and how to fix it.
7. Fixes and retesting. Once you’ve fixed things, we can test again to confirm the issues are resolved, so you can be confident the fixes worked.
What we test for
Depending on scope and technology, that can include broken object-level authorisation, broken authentication, broken function-level authorisation, unrestricted resource consumption, security misconfiguration, improper inventory management, server-side request forgery, and unsafe API consumption. It can also include excessive data exposure, weak access controls, insecure tokens, input validation issues, information disclosure, business logic weaknesses, and insecure endpoints.
Exactly what we assess depends on your API’s architecture, features, technology stack, and agreed scope.
Different APIs, different risks
REST APIs connect web apps, mobile apps, and backend systems. We look at authentication, authorisation, HTTP methods, parameters, responses, and access controls.
GraphQL APIs let clients ask for data in flexible ways. We look at access controls, query handling, information exposure, and configuration.
SOAP APIs are still important in many enterprises. We look at authentication, authorisation, message handling, and configuration.
Microservices often talk to each other through APIs, and a weakness in one service can affect others. We help you understand risk across the service interactions in scope.
Third-party integrations connect you to outside services. We look at how your APIs and integrations handle authentication, authorisation, and data exchange.
Scanning vs. security testing
Automated scanning is good at quickly spotting potential issues across lots of endpoints. Security testing goes deeper, looking at how your API behaves, how access controls hold up, how authentication works, where business logic can be abused, and what attack paths exist. Many teams use automated scanning alongside hands-on testing.
Industries we see it in
APIs are everywhere, and the risks look a little different in each place.
Financial services use APIs for payments, transactions, account data, and integrations, so strong controls protect both sensitive information and business functions.
Healthcare APIs may exchange sensitive patient information. Testing can find weaknesses that could expose protected data or functionality.
E-commerce APIs handle products, customer accounts, orders, payments, and inventory. We look for weaknesses across all of them.
SaaS platforms lean heavily on APIs. We look at authentication, authorisation, tenant separation, and data exposure.
Enterprise environments often run APIs across internal systems, cloud platforms, applications, and third parties. We look for weaknesses across the API environment in scope.
Why Sunvak Boreal
We think like an attacker. We focus on how your APIs could be abused, not just on ticking off technical issues.
Findings your team can use. Your developers and security people should come away knowing what needs to change. We give clear findings and practical fixes.
Risk in context. Not every API vulnerability has the same business impact, so we help you spend your effort where it counts.
A wider view. API security is tied to application, cloud, infrastructure, and network security, and our broader cybersecurity services cover those areas too.
We stay for the fix. Retesting confirms that issues have really been addressed.
When to test
It’s worth testing when you launch a new API, make major changes, add endpoints, connect a third-party service, move an application to the cloud, introduce new authentication, or change access controls. It also makes sense when you handle sensitive information, prepare for security assessments, or follow a security incident, and as part of regular security testing.
Testing after big changes helps you catch problems before they grow.
Who needs it
If you run REST, GraphQL, or SOAP APIs, mobile app APIs, e-commerce, banking, financial, or healthcare APIs, SaaS APIs, internal enterprise APIs, third-party integrations, cloud APIs, or microservices, this is for you. We tailor the assessment to your architecture, business needs, technology, and security goals.
Strengthen your API security
Your APIs connect important parts of your digital world, which makes them a core piece of your security strategy. Finding weaknesses early gives your teams time to fix them before anyone exploits them.
We help you assess your APIs, understand the vulnerabilities, prioritise the risks, and take practical steps to improve your security.
Looking for a professional API security testing team? Contact Sunvak Boreal to talk about your APIs.
FAQs
What is API security testing?
A controlled assessment that finds and validates weaknesses in APIs, including authentication, authorisation, access controls, data exposure, input handling, and configuration.
Why does API security matter?
APIs can give access to sensitive information and important functions. A weakness could lead to unauthorised access or data exposure.
What does testing include?
Depending on scope: authentication, authorisation, access controls, input validation, data exposure, rate limiting, token security, business logic, configuration, and endpoint testing.
What are common API vulnerabilities?
Broken object-level authorisation, broken authentication, broken function-level authorisation, unrestricted resource consumption, security misconfiguration, improper inventory management, and other access control or data exposure issues.
Can you test REST APIs?
Yes. We can assess authentication, authorisation, access control, input handling, data exposure, HTTP methods, configuration, and other security controls.
What about GraphQL?
Yes. We assess GraphQL APIs based on their architecture and features, including access control, query handling, configuration, and data exposure.
Is it the same as vulnerability scanning?
No. Scanning can flag potential issues. Security testing goes deeper into API behaviour, access controls, authentication, business logic, and attack paths.
What happens afterwards?
We document and prioritise the findings, your team fixes them, and we can retest to confirm they’re resolved.
Test your APIs before attackers do
Your APIs are a key part of your digital infrastructure, so don’t leave their security to assumptions. Contact Sunvak Boreal to talk about API security testing and find out where your APIs need stronger protection.