This is a classic example of what what

happens when business logic is enforced

inconsistently between off-chain and

onchain lawyers. Here the back end and

front end enforce a price limit of 100

but smart contract has no or weak

enforcement. The UI displays the

expected value, but an attacker ignores

the front end completely, calls the

contract directly, and uses a much lower

value because the contract doesn't

enforce the same business rule. Then

transaction goes through and that's how

attackers exploit the weaker enforcement

lawyer. So as a result, the back end and

contract states diverge, business rules

break, and the system may end up with

corrupted listings or stolen value.