Incorrect slippage protection for sdt/cvgSdt exchange

Summary

Incorrect slippage protection for sdt/cvgSdt exchange in when withdrawing rewards

Vulnerability Detail

The minimum amount required is incorrectly passed as the current expected swap amount instead of input amount when exchanging from sdt to cvgSdt in the _withdrawRewards() function

                        ICrvPoolPlain _poolCvgSDT = poolCvgSDT;
                        /// @dev Only swap if the returned amount in CvgSdt is gretear than the amount rewarded in SDT
                        _poolCvgSDT.exchange(0, 1, rewardAmount, _poolCvgSDT.get_dy(0, 1, rewardAmount), receiver);

Impact

User's who opt to convert sdt to cvgSdt when cliaming rewards will be front-runned causing loss of funds

Code Snippet

https://github.com/sherlock-audit/2023-11-convergence/blob/main/sherlock-cvg/contracts/Staking/StakeDAO/SdtRewardReceiver.sol#L233C1-L235

Tool used

Manual Review

Recommendation

Pass rewardAmount instead

+++ _poolCvgSDT.exchange(0, 1, rewardAmount, rewardAmount, receiver);
--- _poolCvgSDT.exchange(0, 1, rewardAmount, _poolCvgSDT.get_dy(0, 1, rewardAmount), receiver);

Duplicate of #180

sherlock-audit / 2023-11-convergence-judging

hash - Incorrect slippage protection for sdt/cvgSdt exchange #188