QuantAMM

Summary

In the setQuantAMMSwapFeeTake function, the contract enforces:

However, the error message “Swap fee must be less than 100%” conflicts with the actual code:
• The code uses <= 1e18, which allows a 100% fee.
• The error message suggests strictly less than 100%.

This can cause confusion about whether 100% (_quantAMMSwapFeeTake == 1e18) is allowed or not.

Vulnerability Details

• https://github.com/Cyfrin/2024-12-quantamm/blob/a775db4273eb36e7b4536c5b60207c9f17541b92/pkg/pool-quantamm/contracts/UpdateWeightRunner.sol#L128

• https://github.com/Cyfrin/2024-12-quantamm/blob/a775db4273eb36e7b4536c5b60207c9f17541b92/pkg/pool-quantamm/contracts/UpdateWeightRunner.sol#L143

Impact

Tools Used

Manual audit

Recommendations

1. Clarify the Condition or the Error Message

   • If exactly 100% is permitted, the error message should read “Swap fee must be ≤ 100%.”

   • If the intention is to disallow 100%, then change the code to
     require( _quantAMMSwapFeeTake < 1e18, "Swap fee must be less than 100%" );

2. Maintain Consistency in all similar checks (for example, “uplift fee must be less than 100%” in the setQuantAMMUpliftFeeTake function).