Changing one ID can be enough
If the API does not check whether the requested data really belongs to the user, changing a single number can expose other customers’ data.
This type of flaw ranks first on the OWASP API Top 10.
API testing
What could an attacker reach through your APIs?
We check whether an attacker could access other customers’ data or protected functions simply by modifying API requests.
Business risk
Not every attack looks like a break-in.
APIs connect your systems and business processes. If authorisation or business logic is flawed, a legitimate-looking request can grant access to protected data or operations – often without triggering an alert.
A luxury room for one cent
In Spain, a hacker booked luxury hotel rooms for one euro cent because the booking system did not check whether the amount paid matched the price.
It was not a technical masterstroke but a business logic flaw – exactly what an API test looks for.
Abuse can stay hidden
A flawed API can allow data to be leaked, altered or used without authorisation.
Often without any error message or security alert.
Every finding comes with evidence and concrete remediation steps your development team can follow. If a mobile app or web front end is built on the API, they can be tested together.
Request a consultationMethodology
How we test APIs from an attacker’s perspective.
Testing starts with understanding how the APIs work and what role they play in the business. We combine automated checks with manual testing and real-world attack scenarios, so that subtle logic flaws come to light alongside common vulnerabilities.
- API endpoints
- Related integrations
- Systems supporting critical business processes
- OWASP API Security Top 10 (2023) risks
- Authentication and authorisation flaws
- Data exposure and misconfigurations
- Abuse of existing API functions
- Privilege escalation paths
- Manipulation of business processes
- Discrepancies between documentation and behaviour
- Missing validation rules
- Exploitable design assumptions
- Data flows between systems
- How services interact
- Assumptions built into the design
- Exploitability in real situations
- Impact on the affected environment
- Concrete, actionable remediation steps
Insights
API security insights.
An API can look secure on paper and still be attackable in real use. Our articles show how flawed assumptions and weak business logic lead to exploitable vulnerabilities.
Consultation
Security starts with a conversation.
No sales pitch – just a focused conversation about your business continuity and operational risk.