Over the past few years, API security has gone from a relatively niche concern to a headline issue. A slew of high-profile breaches and compliance mandates like PCI DSS 4.0 have woken security teams up to the reality that APIs are the front door to their data, infrastructure, and revenue streams.
OWASP recently published its first-ever Business Logic Abuse Top 10 List; a clear indication that the industry is taking API security and all its nuances seriously. As Ivan Novikov, Wallarm’s CEO and a key contributor to the project put it:
“It’s incredibly important for the community to have a common language around business logic attacks. These types of attacks transcend a specific software stack or technology. They don’t fit into the existing taxonomies, but they are being actively exploited by attackers today.”
In this article, we’ll explore the OWASP Top 10 for Business Logic Abuse, why it’s important and, crucially, how Wallarm can help when it comes to business logic abuse and APIs.
Why this List Matters
Business logic abuse isn’t a theoretical problem; it’s a daily reality in production environments across all industries and geographies. And, to make matters worse, these flaws rarely leave the obvious traces associated with more traditional vulnerability exploitation.
Real World Impacts: The RBI International Drive-Thru Incident
In September 2025, Restaurant Brands International (RBI International), owner of Burger King, Tim Hortons, and Popeyes, was found to have exposed multiple API security flaws tied to its drive‑thru operations. Attackers could generate authentication tokens without proper checks, access or eavesdrop on drive‑thru audio, and elevate privileges from regular customer to admin.
This scenario maps to several OWASP Business Logic Abuse Top 10 categories:
- BLA6: Missing Transition Validation (MTV) – The initial sign up endpoint didn’t provide any validation that the individual creating an account was a valid employee.
- BLA9: Broken Access Control (BAC) — The “createToken” endpoint allowed any user to request tokens without authentication.
- BLA9: Broken Access Control (BAC) — Privilege escalation from customer to admin shows failures in enforcing role‑based permissions.
- BLA8: Internal State Disclosure (ISD) — Eavesdropping on live audio and exposure of personal info amounts to unintended disclosure of internal state or data.
- BLA10: Shadow Function Abuse (SFA) – An open GraphQL endpoint allowed for both introspection queries and provided a signup that bypassed email validation.
The Broader Landscape: Fintech and Ecommerce
The problem extends far beyond telecommunications. Fintech and ecommerce organizations frequently fall victim to transactional workflow abuse. For example, attackers might cancel and reinitiate payments or send multiple parallel requests to exploit timing gaps and system assumptions. These types of abuses map to several OWASP categories, including:
- BLA1: Action Limit Overrun (ALO) — Abusing single-use or limited actions such as coupons, refunds, or retries.
- BLA2: Concurrent Workflow Order Bypass (CWOB) — Exploiting parallel processes to skip mandatory workflow steps.
- BLA7: Resource Quota Violation (RQV) — Overwhelming a system’s quota limits to cause disruption or gain advantage.
Traditional Security Falls Short
Unlike code injection or misconfigurations, business logic abuse thrives when systems function exactly as intended, but not as expected. As a result, these threats often bypass traditional security tools like Web Application Firewalls (WAFs), scanners, or static analysis, which are typically designed to detect known patterns of malicious code or misconfigurations.
The PCI DSS 4.0 Imperative
With PCI DSS 4.0 Requirement 6.2.4 explicitly mandating the detection and prevention of logic abuse, security teams can no longer treat it as an edge case. The OWASP Top 10 for Business Logic Abuse provides the industry with a crucial framework to assess, prioritize, and defend against these increasingly prevalent and sophisticated threats.
The OWASP Business Logic Abuse Top 10 (2025)
| Abuse | Impact |
| BLA1: Action Limit Overrun (ALO) | Unsynchronized requests or repeated actions bypass usage limits (e.g., coupon abuse, refund replay). |
| BLA2: Concurrent Workflow Order Bypass (CWOB) | Attackers exploit concurrency to skip mandatory workflow steps. |
| BLA3: Object State Manipulations (OSM) | Altering objects in unexpected states to bypass business rules (e.g., shipping before payment). |
| BLA4: Malicious Logic Loop (MLL) | Infinite or recursive loops drain resources or disrupt workflows. |
| BLA5: Artifact Lifetime Exploitation (ALE) | Abusing tokens, sessions, or credentials that live longer than intended. |
| BLA6: Missing Transition Validation (MTV) | Workflow transitions proceed without required validation (e.g., bypassing approval). |
| BLA7: Resource Quota Violation (RQV) | Exhausting or exploiting system resource quotas to degrade service. |
| BLA8: Internal State Disclosure (ISD) | System behavior unintentionally reveals sensitive internal state. |
| BLA9: Broken Access Control (BAC) | Inadequate enforcement of access rules enables unauthorized actions. |
| BLA10: Shadow Function Abuse (SFA) | Exploiting undocumented or hidden functions not intended for public use. |
How Wallarm Protects Against Business Logic Abuse in APIs
Business logic flaws are subtle and difficult to detect with traditional tooling. That’s why we’ve designed Wallarm from the ground up to defend against them in APIs; not just at the surface, but deep within the application logic itself.
When attackers exploit workflows, Wallarm maintains visibility into how APIs are supposed to function, detecting when requests veer off course. For example, if an attacker tries to exploit orphaned tokens or manipulate multi-step flows, our business logic identification, behavioral baselining, and stateful inspection catch the inconsistency before damage is done.
Moreover, our schema validation enforces strict checks on data types, stopping smuggling attempts that might bypass loose logic. And when logic loops, replays, or concurrency flaws emerge, our anomaly detection, token verification, and rate limiting work in concert to prevent resource exhaustion or financial abuse.
We also understand that access isn’t just about endpoints, it’s about context. Wallarm evaluates authorization checks, validates state transitions, and ensures quota boundaries are respected on every call, across every API type. Mitigating business logic attacks requires more than just blocking a request or blocking an IP address. These attacks occur at the application-level, and Wallarm mitigates them by blocking the API session in which the behavior occurs.
Put simply, each of the OWASP Top 10 categories maps to a protection capability within Wallarm’s platform. But more importantly, our system treats logic as a living, evolving layer of your security posture; not just a checklist item.
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