QuantAMM

Summary

In the setQuantAMMUpliftFeeTake function:

the code incorrectly stores the uplift fee in quantAMMSwapFeeTake rather than using a dedicated variable (e.g., quantAMMUpliftFeeTake). This mixes two separate fees (swap fee vs. uplift fee) into a single state variable, causing confusion or unintended overrides.

Vulnerability Details

• https://github.com/Cyfrin/2024-12-quantamm/blob/a775db4273eb36e7b4536c5b60207c9f17541b92/pkg/pool-quantamm/contracts/UpdateWeightRunner.sol#L145

Impact

• Fee Confusion: Because both the swap fee and the uplift fee are stored in quantAMMSwapFeeTake, the actual values for each may become unclear.

• Functional Errors: Any logic relying on a distinct “uplift” fee might incorrectly read the “swap” fee, or vice versa.

Tools Used

Manual audit

Recommendations

1. Use a Separate State Variable. Introduce a dedicated variable, for example:

and assign _quantAMMUpliftFeeTake to that variable in the setQuantAMMUpliftFeeTake() function:

1. Adjust Getter.
   Update the getQuantAMMUpliftFeeTake() function to return this new quantAMMUpliftFeeTake variable.