Root + Impact

Description

• Expected behavior: The CustomerEngine should call reputation() on the CompanyGame contract using valid Vyper syntax so the reputation check executes at runtime. A correct inter-contract view call should compile and return the reputation value.

• Actual behavior: The code uses a staticcall-style expression that is not valid Vyper syntax: # (from supplied CustomerEngine.vy)

  rep: uint256 = staticcall CompanyGame(self.company).reputation()

  
  

Risk

Likelihood

High: This is a clear syntactic/semantic error that will surface at compile time if not fixed.

Impact

1.High: The contract may fail to compile (blocking deployment), or if compiled with a changed implementation the reputation check may be bypassed, allowing low-reputation demand to proceed.

2.Functional break: CustomerEngine cannot safely gate demand by reputation, impacting economic simulation and allowing unvalidated sales.

Proof of Concept

Explanation

Vyper uses interface calls like CompanyGame(self.company).reputation() to perform external view calls. staticcall is a low-level EVM operation; in Vyper you either call the interface method directly (preferred) or use raw_call and decode the returned bytes. Mixing staticcall with the interface syntax is invalid.

Leaving the line as-is results in a compiler error (deployment blocked) or in developers substituting incorrect logic that bypasses reputation checks — both are unacceptable.

Recommended Mitigation

Replace the invalid staticcall expression with a proper Vyper interface call

Or

Option B — Defensive | Use raw_call and validate returned bytes (if the counterparty may be non-conforming):