# Stuck ETH in Curve exchanges due to sending msg.value to the exchange instead of amountIn Crit/High · Three Sigma · Private DeFi access · 26th February, 2024 Finding 3S-SG-C06 of the Singularity security review. - Protocol: https://www.thesingularity.network/ - Report: /reports/singularity - Source: https://cdn.sanity.io/files/qoqld077/production/45b8aac56a2b8e3b557df4329ac9bf8220b64012.pdf --- ### Description The curve exchanges allow users who deposited to use their note commitments to swap for other assets. Thus, they have already deposited the ETH, but the exchanges still [require](https://github.com/portalgateme/darkpool-v1-zk-contracts-fork/blob/master/contracts/defi/curve/CurveSingleExchangeAssetManager.sol#L146) the amountIn to be msg.value, leading to stuck ETH. POC [here](https://github.com/portalgateme/darkpool-v1-zk-contracts-fork/blob/fuzzing/test/foundry/CurveSingleExchangeAssetManager.t.sol#L68). ### Recommendation Replace IExchange(exchangeContract).exchange{value: msg.value} by IExchange(exchangeContract).exchange{value: amountIn}. ### Status Addressed in [#8b300f0](https://github.com/portalgateme/darkpool-v1-zk-contracts-fork/commit/8b300f07a28f2c073154c8de3e9e90ba64ef1934). --- Related findings: - [User to sell the last supply will make the exchange contribution forever stuck](https://0xsimao.com/findings/mento-sell-supply-contribution-stuck): Mento - [Depositing to another receiver othan than `msg.sender` will lead to stuck funds by increasing `avgStart` without claiming](https://0xsimao.com/findings/exactly-protocol-update-staking-contract-ii-othan-stuck-increasing-avg): Exactly Protocol Update - Staking Contract - [Incorrect redeemAmount Is Accounted Due To Not Accounting For The Exchange Rate](https://0xsimao.com/findings/cork-protocol-redeem-accounted-accounting-exchange): Cork Protocol - [Midnight constructor can use `msg.sender` instead of reading `roleSetter` from storage](https://0xsimao.com/findings/morpho-midnight-midnight-reading-setter-storage): Morpho Midnight