Business logic testing evaluates the security and integrity of an application’s core workflows and rules, focusing on vulnerabilities that arise from flawed design rather than code-level weaknesses. 

Unlike traditional vulnerabilities (e.g., SQL injection), these flaws exploit legitimate functionalities used in unintended ways, making them harder to detect with automated tools.. Below are critical areas covered in business logic testing:  

Business Logic Data Validatio

Ensures data aligns with expected business rules at all interaction points. Weak validation allows attackers to submit malformed inputs (e.g., negative prices, oversized files) or bypass client-side checks[1][4]. Testing involves sending invalid data to verify server-side rejection and consistency across workflows].  

Ability to Forge Requests

Tests whether applications accept manipulated requests through hidden parameters, modified headers, or tampered payloads. Attackers exploit this to bypass authentication, escalate privileges, or alter transaction outcomes.  

Integrity Checks

Validates data consistency and accuracy during operations like updates, transfers, or migrations. Includes verifying checksums, audit logs, and error handling to prevent corruption or unauthorized alterations  

Process Timing 

Assesses time-sensitive operations (e.g., session expiration, transaction delays) for vulnerabilities like race conditions. For example, attackers might exploit delays in payment processing to manipulate order statuses[1][5].  

Replay Attack

Checks if intercepted valid requests (e.g., authentication tokens, payment confirmations) can be reused maliciously. Mitigated through nonce values, timestamp validation, or single-use tokens[5].  

Circumvention of Work Flows 

Identifies bypasses in multi-step processes (e.g., skipping checkout steps or approval stages). Testing involves manipulating URLs, parameters, or UI elements to access restricted actions[4][5].  

Abuse of Functionality

Explores unintended use of features, such as exploiting search functions for data scraping or misusing APIs for unauthorized data access. Requires understanding legitimate use cases and creative misuse scenarios[4][5].  

File Upload Vulnerabilities  

Tests file-handling mechanisms for risks like malicious executable uploads, path traversal, or insufficient MIME-type validation. Attackers may upload harmful files to execute code or overwrite critical system files[5].  

Business logic testing demands manual analysis and threat modeling to simulate real-world misuse, as automated tools often miss these context-specific flaws. Regular audits, server-side validation, and adherence to frameworks like OWASP’s WSTG are critical for mitigation].