Definition
The application enforces its rules correctly, but one of those rules trusts something the client controls: a price, a quantity, a discount code, a currency, or the order in which steps occur.
Why scanners do not find this
There is no signature. Nothing is malformed, no library is outdated, and no payload looks hostile. The request is well-formed and the response is a success. Only someone who understands what the workflow is supposed to mean can tell that the outcome is wrong.
Shapes this takes
- A value the server should compute is instead accepted from the client
- A step assumed to happen in a fixed order can be skipped or replayed
- A one-time action can be applied repeatedly
- A discount or credit can be combined in ways never intended
- A currency or rounding decision can be influenced by the requester
- User
- Transaction Workflow
- Manipulated Value
- Unauthorized Price
- Financial Impact
Each hop validated by successful exploitation
Tags
- business logic
- ecommerce
- transactions