Sometimes the app works exactly as designed. That’s the problem.
An application can have solid encryption, well-configured infrastructure, and rock-solid authentication, and still let a customer approve their own refund, skip a required approval step, or reach a screen meant only for staff. None of that trips a technical alarm. The app is doing exactly what its code says to do. The code just says the wrong thing.
That’s the whole reason logic and authorization testing exists as its own discipline. Automated scanners are great at finding a missing security header or an outdated library. They’re much worse at knowing that a customer shouldn’t be able to approve their own transaction. We test for exactly this: the gap between “technically working” and “actually secure.”
What we’re actually testing
Two related but distinct things.
A logic flaw is when an application does something that violates the business rule it was supposed to enforce, letting someone skip a step, repeat an action that should only happen once, or manipulate a value that shouldn’t be touchable.
An authorization vulnerability is when the application fails to properly check whether a specific user is actually allowed to do the thing they’re attempting.
In practice, this covers things like a user reaching another user’s account, a standard user stumbling into an admin function, skipping required workflow steps, changing transaction values that should be locked, replaying a completed action, reaching functionality through a different route than the UI intends, tampering with object identifiers, or bypassing an approval process entirely.
We test by interacting with your application the way a real, motivated user would, not the way the happy-path demo assumes they will.
Why this deserves separate attention
These vulnerabilities are genuinely hard to catch because they’re specific to your business, not to some generic vulnerability class a scanner has memorized. Testing here uncovers broken access controls, privilege escalation in both directions, workflow bypasses, business rule violations, missing authorization checks, parameter tampering, object-level and function-level authorization gaps, multi-step process bypasses, transaction manipulation, and logic issues tied to race conditions.
A technically secure application can still hand out unauthorized access if its business rules aren’t actually enforced where it counts.
What we actually test
Understanding your roles first. Before we can test authorization, we need to know how your app actually distinguishes between users, standard users, administrators, managers, support staff, partners, vendors, whatever roles exist. Then we check whether permissions are consistently enforced across every part of the application, not just the parts someone remembered to lock down.
Horizontal authorization. Can one user reach another user’s stuff, despite having the exact same privilege level? We try to reach another user’s profile, another customer’s order, another account’s records, someone else’s documents or messages, or resources belonging to a different tenant entirely.
Vertical authorization. Can a lower-privileged user climb into functionality meant for someone higher up? Standard users reaching admin functions, customers reaching staff tools, employees reaching management features, regular users modifying settings that should be locked to them.
Function-level authorization. A function can be hidden from the interface and still be reachable through a direct request. We check whether your backend actually verifies authorization independently, or whether it’s just trusting that the UI hides the button.
Object-level authorization. Applications constantly use identifiers to reach specific users, accounts, orders, invoices, documents. We test whether the app actually confirms the authenticated user is allowed to touch that specific object, this is where BOLA-style risks live.
Workflow bypass. Business processes often need a sequence: submit a request, complete verification, get approval, complete payment, receive the service. We test whether that sequence can be skipped, repeated, reordered, or otherwise manipulated to get to the end without actually earning it.
Parameter and transaction manipulation. We check whether values like prices, quantities, account identifiers, transaction amounts, status flags, user roles, discounts, or approval states can be changed in ways that bypass the rules they’re meant to enforce.
Privilege escalation. We test whether users can obtain more functionality or permission than their account was ever supposed to have, horizontal, vertical, or both.
Multi-tenant boundaries. For SaaS platforms specifically, we test whether one organisation’s users can cross into another organisation’s data. This is one of the more serious findings we look for, because it can affect every customer at once, not just one account.
State and workflow integrity. We check whether completed operations can be repeated, finished transactions can be modified after the fact, expired actions can be reused, or application state can be pushed into a sequence that was never supposed to be possible.
How we run this
Scope and planning. We identify your application’s functionality, user roles, business processes, APIs, and testing boundaries.
Role mapping. We build a real understanding of your roles, permissions, workflows, and the business operations that actually matter.
Access control mapping. We define exactly which functions, resources, and objects each role should and shouldn’t be able to reach.
Authorization testing. We test across different roles, actively trying to access what should be restricted.
Business logic testing. We stress-test key workflows for unexpected sequences, missing checks, parameter tampering, and rule bypasses.
Cross-user and cross-tenant testing. Where it applies, we test whether users can reach resources belonging to other users, roles, or entire organisations.
Impact validation. We confirm exactly what unauthorized action or data access is genuinely possible, not just theoretically plausible.
Reporting and retesting. You get a clear document on the affected functionality, the evidence, the impact, and how to fix it. Once you’ve made changes, we can confirm they held.
What tends to show up
Broken access control. Broken function-level and object-level authorization. Horizontal and vertical privilege escalation. Workflow bypass. Business rule violations. Missing authorization checks. Parameter and transaction manipulation. Multi-tenant data exposure. Unauthorized access to admin functions. Role and status manipulation. Approval bypass. Step skipping. Replay of actions that should only happen once. Excessive permissions. Authorization that’s inconsistent between your web interface and your API, which is a surprisingly common gap.
Logic flaws vs. authorization vulnerabilities
They overlap a lot in practice, but they’re not identical. A logic flaw is about how the business rule or workflow was actually implemented. An authorization vulnerability is about whether the app checks if a user is allowed to do something at all.
A concrete example: letting a customer approve their own refund is a business logic problem, the rule itself is wrong. Letting a regular customer reach an admin-only refund function is an authorization problem, the check itself is missing. Applications frequently have both.
Authorization testing vs. authentication testing
Authentication answers “who are you?” Authorization answers “what are you allowed to do?” An app can nail authentication completely and still fail authorization badly, correctly identifying a user while incorrectly deciding what that user can touch. That’s exactly why authorization deserves its own dedicated testing, rather than being assumed to be fine because login works.
Logic flaw testing vs. automated scanning
Scanners are genuinely good at what they do: missing headers, outdated components, known vulnerability patterns. What they can’t do is understand your business. A scanner has no idea that a customer approving their own transaction is a problem, because nothing about that request looks technically malformed. That’s exactly the gap manual testing fills.
Who this is for
Banking applications. Fintech platforms. E-commerce applications. Healthcare platforms. SaaS applications. Enterprise and customer portals. Insurance platforms. Booking systems. Subscription platforms. Marketplace applications. Multi-tenant applications. Administrative portals. Any API-driven application.
It matters most anywhere transactions, sensitive data, multiple user roles, or genuinely complex workflows are involved, which describes most applications that actually run a real business.
When to test
Before launching a new application. Before releasing major functionality. After adding new user roles or changing authorization rules. After introducing new workflows. After major API changes. Following an application redesign. During regular penetration testing. After a security incident. Before handling sensitive transactions. Before launching a multi-tenant platform.
Regular testing matters because business processes change constantly, and every change is a fresh chance for a new authorization gap to sneak in unnoticed.
How to actually reduce this risk
Enforce authorization server-side, always, never trust the client. Apply least-privilege principles genuinely. Centralize authorization logic where it makes sense, rather than scattering ad-hoc checks everywhere. Validate access on every single protected resource, not just the obvious ones. Never rely on a hidden UI element as your only security control. Validate workflow state on the backend. Enforce business rules server-side. Keep administrative functionality genuinely separated. Apply consistent authorization across both your web interface and your APIs. Test different roles deliberately. Log important authorization events. Review authorization every time you make a major application change.
Why work with us
We combine actual application security testing with a real understanding of business workflows and access control requirements, not just a generic checklist. We test across different roles to find unauthorized access and privilege escalation, and we check authorization consistently across both your interfaces and your backend APIs. Anything we find gets validated to confirm its real impact, not just flagged as theoretically concerning. Findings come with clear evidence and practical fixes, and once you’ve made changes, we retest to confirm authorization and business logic controls are genuinely working as intended.
Bottom line
Strong authentication doesn’t automatically mean strong authorization. A workflow that looks correct from the interface can still hide backend logic that’s badly broken. This kind of testing finds the less obvious problems, the ones that live in how users, roles, resources, transactions, and business processes actually interact, and helps you catch what traditional vulnerability scanning genuinely cannot see.
FAQs
What is logic flaw testing?
Testing that checks whether an application can be manipulated into performing actions that violate its intended business rules or workflow.
What is authorization testing?
Testing that checks whether users can access only what’s actually permitted for their role, nothing more.
What’s the difference between authentication and authorization?
Authentication confirms who you are. Authorization determines what you’re allowed to do once you’re confirmed.
Can this find privilege escalation?
Yes, both horizontal, between similarly privileged users, and vertical, from lower-privileged accounts reaching higher-privileged functionality.
What is business logic testing exactly?
Examining your workflows, rules, transactions, and processes to see whether they can be manipulated or bypassed in ways that violate what they’re supposed to enforce.
Can this be done on APIs?
Yes, and it needs to be. Backend authorization should hold regardless of whether functionality is reached through a web interface or a direct API call.
Is BOLA part of this?
Yes. Broken Object Level Authorization is exactly this kind of failure, where the app doesn’t properly verify a user is allowed to access a specific object.
Can multi-tenant applications be tested?
Yes. We specifically test whether users or organisations can cross tenant boundaries and reach data belonging to someone else.
How often should this be tested?
During development, after major feature or authorization changes, and as part of regular penetration testing.
What’s in the report?
Affected functionality, the roles tested, evidence, security impact, reproduction details, risk context, remediation recommendations, and retesting results.
Test your application logic and authorization controls
Talk to Sunvak Boreal about your application. Let’s find out whether it’s quietly letting people do things it was never supposed to allow.