XVader.sol : loss of user funds during 'leave' function

Handle shri4net Vulnerability details Impact Unintended Fee is charged to user while using 'leave' function in XVader.sol as part of the voting/governance. Proof of Concept Ref contracts/x-vader/XVader.sol, function leave Ref contracts/tokens/Vader.sol, function transfer Example, User locks 100...

Inconsistent balance when supplying transfer-on-fee or deflationary tokens

Handle Reigada Vulnerability details Impact In the contract StakingRewards, the stake function assume that the amount of stakingToken is transferred to the smart contract after calling the safeTransferFrom function and thus it updates the balances mapping. However, this may not be true if the...

Wrong assumption when updating token balance

Handle rfa Vulnerability details Impact When there is a movement of token in the swap and addliquidity function, the balances reserve , is updated based on the difference between the before and after the user transfer the token, however if there is a user that accidently send a token to this...

Trades where toToken is feeOnTransferToken might send user less tokens than finalAmountMin

Handle kenzo Vulnerability details Slingshot's executeTrades checks that the trade result amount to be sent to the user is bigger than finalAmountMin, and after that sends the user the amount. But if the token charges fee on transfer, the final transfer to the user will decrease the amount the us...

Fee on transfer tokens do not work within the protocol

Handle tensors Vulnerability details Fee on transfer tokens transfer less tokens in than what would be expect. This means that the protocol request incorrect amounts when dealing with these tokens. The protocol should use stored token balances instead of transfer for calculating amounts. --- The...

fee possibly send in the wrong way in exitVaultFillingVaultInitiate

Handle gpersoon Vulnerability details Impact The functions exitZcTokenFillingZcTokenInitiate and exitVaultFillingVaultInitiate are kind of similar, however the processing of the fee is different. exitZcTokenFillingZcTokenInitiate send the fee from o.maker exitVaultFillingVaultInitiate sends the f...

Swivel: implementation for initiateZcTokenFillingZcTokenExit is incorrect

Handle itsmeSTYJ Vulnerability details Impact In initiateZcTokenFillingZcTokenExit , this comment // transfer underlying tokens - the premium paid + fee in underlying to swivel from sender is incorrect because you are actually transferring the underlying tokens - premium paid to the maker from...

User can get more/less interest than required

Handle csanuragjain Vulnerability details Impact It seems that owner must not get interest for transfer fee which is collected using transferNotionalFee No interest is calculated on owner side before reducing the owner notional amount But this can simply be bypassed if owner adds new notional whi...

ConstantProductPool & HybridPool: Adding and removing unbalanced liquidity yields slightly more tokens than swap

Handle GreyArt Vulnerability details Impact A mint fee is applied whenever unbalanced liquidity is added, because it is akin to swapping the excess token amount for the other token. However, the current implementation distributes the minted fee to the minter as well when he should be excluded. It...

HybridPool's flashSwap gives the total fee to barFeeTo

Handle 0xsanson Vulnerability details Impact In HybridPool's flashSwap function there's a transfer to barFeeTo transfertokenIn, fee, barFeeTo, false; Here fee = amountIn swapFee / MAXFEE is the total swap fee. However it should transfer out only a fraction of it barFee/MAXFEE otherwise liquidity...

hybrid pool uses wrong non_optimal_mint_fee

Handle broccoli Vulnerability details Impact When an lp provider deposits an imbalance amount of token, a swap fee is applied. HybridPool uses the same nonOptimalMintFee as constantProductPool; however, since two pools use different AMM curve, the ideal balance is not the same. ref:...

HybridPool's flashSwap sends entire fee to barFeeTo

Handle cmichel Vulnerability details The HybridPool.flashSwap function sends the entire trade fees fee to the barFeeTo. It should only send barFee fee to the barFeeTo address. Impact LPs are not getting paid at all when this function is used. There is no incentive to provide liquidity. Recommende...

Basket.handleFees() (contracts/Basket.sol#110-129) performs a multiplication on the result of a division

Handle 0xalpharush Vulnerability details Impact Users can burn tokens and evade fees by backrunning other transactions that result in handleFee being called. Proof of Concept Following another transaction that results in lastFee being updated, an attacker can call burn and withdraw their tokens...

Fee calculation is potentially incorrect

Handle itsmeSTYJ Vulnerability details Impact More fees are actually charged than intended Mitigation Steps Basket.sol line 118 Assume that license fee is 10% i.e. 1e17 and time diff = half a year. When you calculate feePct, you expect to get 5e16 since that's 5% and the actual amount of fee to b...

Fee on transfer tokens can lead to incorrect approval

Handle hrkrshnn Vulnerability details Fee on transfer tokens can lead to incorrect approval The createBasket function does not account for tokens with fee on transfer. function createBasketuint256 idNumber external override returns IBasket // ... for uint256 i = 0; i bProposal.weights.length; i++...

convert fails for fee-on-transfer tokens

Handle 0xsanson Vulnerability details Impact The Controller contract can call converter.convert inside earn and withdraw functions, after transferring amount of tokens to the Converter contract. This contract assumes that it has received exactly amount tokens, however this isn't true for...

Vault.balanceOfThis values all tokens equally

Handle cmichel Vulnerability details The Vault.balanceOfThis function values all tokens equally. They are normalized to 18 decimals and then simply added up: for uint8 i; i tokens.length; i++ address token = tokensi; // adds up different tokens here, treating them as exactly equal value 1.0 A = 1...

Unhandled reverts from Cosmos to Eth batches can cause *Denial Of Service*

Handle hack3r-0m Vulnerability details At the above-mentioned places in Gravity contract, it makes external call to a function to transfer erc20 token. This can cause revert in cases where erc20 safeTransfer fails for e.g erc20 contract has blacklisted address of gravity contract to alllow...

Miner fails to get block template when a cell used as a cell dep has been destroyed.

Impact The RPC getblocktemplate fails when a cell has been used as a cell dep and an input in the different transactions. Say cell C is used as a dep group in the transaction A, and is destroyed in the transaction B. The node adds transaction A first, then B into the transaction pool. They are bo...

Crypto-scams you should be steering clear of in 2021

A fair few cryptocurrency scams have been doing the rounds across 2021. Most of them are similar if not identical to tactics used in previous years with an occasional twist. Here’s some of the most visible ones you should be steering clear of. Recovery code theft Many Bitcoin wallets make use of...