Business logic integrity is the security of an application’s rules, decisions, and workflows. It means the system produces the right outcome for the right reason, and that attackers cannot alter calculations, state changes, approvals, or settlement steps by abusing normal features.
This matters because many cyber attacks do not break encryption or inject malware; they exploit trusted business processes. An attacker may change a parameter, replay a request, reorder steps, or trigger an edge case to get a refund, bypass a limit, manipulate a score, or alter a transaction result. In software supply chains, a library can appear normal while hiding code that targets a specific workflow. Defenses include strict server-side validation, strong authorization checks, invariant testing, audit logging, and code reviews that focus on business rules as well as security controls. If the logic itself can be bent, the application may remain available but still fail its purpose.