Unsafe usage of ERC20 transfer and transferFrom

Lines of code Vulnerability details Impact Some ERC20 tokens functions don’t return a boolean, for example, USDT, BNB, OMG. So the LowLevelERC20Transfer contract simply won’t work with tokens like that as the token. Proof of Concept USDT’s transfer and transferFrom functions don't return a bool,...

Upgraded Q -> M from #43 [1668210521611]

Judge has assessed an item in Issue 43 as M risk. The relevant finding follows: Q-02 - Huge trust assumption in recoverErc20 Reward tokens are transferred into this contract when a pledge is created. The comment notes " Recovers ERC2O tokens sent by mistake to the contract", but this function can...

ETH can be accidentally sent with ERC20 in sendOutTokenOrETH function

Lines of code Vulnerability details Impact ETH can be accidentally sent with ERC20 in sendOutTokenOrETH function User who wants to send ERC20 due to payable function can write a value in the value field Proof of Concept contracts/utils/LineLib.sol: 33 / 34: function sendOutTokenOrETH 35: address...

Missing ReEntrancy Guard to sendOutTokenOrETH function

Lines of code Vulnerability details Proof of Concept There is no re-entry risk on true ERC-20 tokens that work according to the spec i.e. audited, etc.. However you can write a malicious ERC-20 with custom transferFrom or approve that have re-entrancy hooks to attack a target. Furthermore ERC-777...

SpigotedLineLib::trade won’t work with tokens with approval race protection (USDT)

Lines of code Vulnerability details Proof of Concept Some tokens e.g. USDT, KNC do not allow approving an amount M 0 when an existing amount N 0 is already approved. This is to protect from an ERC20 attack vector described here. The problem is the code in trade is the following...

LineLib.sendOutTokenOrETH() may not be compatible with contract receiver because of use of transfer()

Lines of code Vulnerability details Impact LineLib.sendOutTokenOrETH may revert when its receiver is a contract, preventing it from receiving ETH, and thus from much of the functionality of the protocol. Proof of Concept LineLib.sendOutTokenOrETH is as follows. / @notice - Send ETH or ERC20 token...

Logic in LineLib does not work correctly with fee-on-transfer tokens

Lines of code Vulnerability details Proof of Concept Some tokens take a transfer fee e.g. STA, PAXG, some do not currently charge a fee but may do so in the future e.g. USDT, USDC. The code currently receives ERC20 tokens but does not account for the potential fees paid in the transfer. If such a...

Not checking amount of received ERC20 tokens

Lines of code Vulnerability details Description There are ERC20 tokens, which apply intenal fee on transfers such as USDT, so that amount of received tokens could differ from requested amount. There is a line where contract receives facilityFee as an amount of tokens. The same variable is used on...

Potential DoS when closing a credit nominated in ETH in the LineOfCredit contract

Lines of code Vulnerability details When closing a credit that was issued in ETH, the LineOfCredit contract will send the lender his deposit and any accrued interests using the address.transferamount function, which may fail and revert the whole function, leading to an eventual DoS. Impact The...

ERC20 and ETH might be returned back to the wrong originator

Lines of code Vulnerability details Impact Detailed description of the impact of this finding. Assume the address of erc20EnabledLooksRareAggregator was maliciously changed to fakeerc20EnabledLooksRareAggregator during an execution of LooksRareAggregator.execute then, the malicious user might for...

msg.sender token balance is not checked before calling safeTransferFrom function

Lines of code Vulnerability details Impact createAuction FUNCTION and bid FUNCTION: Without checking the msg.sender token balance the transfer function may be failed to transfer token from msg.sender to contract address . this may cause a transactions failures. Same instance in 2 times PROOF OF...

baseToken AND quoteToken CAN BE THE SAME ERC20 TOKENS, RESULTING IN TRICKING BIDDERS TO LOSE THEIR TOKENS

Lines of code Vulnerability details Impact createAuction can be called by anyone to create auctions. One of the input parameter that this function requires is auctionParams. Since the createAuction function doesn't check that baseToken AND quoteToken are same or not, an Adversary can create an...

Reentrancy in createAuction() function

Lines of code Vulnerability details Impact Some ERC20 tokens missing return values and don't fail in case of an unsuccessful transfer. Also, ERC777 tokens could call the tokens receivers during the transfer. If baseToken would be such a token that combines both properties - this could lead to a...

VARIABLE BALANCE TOKEN ASSOCIATED WITH LOSS AND LOCKING OF FUNDS

Lines of code Vulnerability details Impact ERC20 tokens that are either deflationary or re-basing down could have their respective balance change. The balance could become insufficient at the time of withdraw, refund or cancel to the bidders whose funds will be locked due to DOS. The way to take...

Bridge should not allow ERC20 tokens with double-entry point

Lines of code Vulnerability details Impact If a token with double-entry point is escrowed in L1 bridge, the user could withdraw their token through the other entry point, thus rugpulling the bridge. And when they actually withdraw from L2, they will take other users' funds from the bridge. Proof ...

Hacker can front-run the L2 ERC20 token deployment.

Lines of code Vulnerability details Impact hacker can front-run the L2 ERC20 token deployment to block L2 ERC20 token finalizeDeposit Proof of Concept I intend to prove this piece of code is front-runnable by hacker: /// @notice Finalize the deposit and mint funds /// @param l1Sender The account...

Approve front-running attack in DBR.sol

Lines of code Vulnerability details Impact An attacker could front-run an approve transaction to get an overall bigger amount approved. Proof of Concept This is the approve function of the DBR token. function approveaddress spender, uint256 amount public virtual returns bool...

Owner can bypass ERC20 recovery restrictions and take all rewards

Lines of code Vulnerability details Impact There is a function that is intended to be used to recover ERC20 tokens that were sent to the WardenPledge contract by accident. The function is only usable by the owner and contains a check that no tokens can be taken which are currently whitelisted as...

recoverERC20 can drain user's funds

Lines of code Vulnerability details recoverERC20 function is deployed so users who have accidently sent erc20 tokens to the contract be able to recover them. recoverERC20 uses ifminAmountRewardTokentoken != 0 revert Errors.CannotRecoverToken; to check if token was set to one of the RewardTokens o...

Owner can bypass reward token protection in recoverERC20 to instantly steal all tokens in contract

Lines of code Vulnerability details Description WardenPledge contract has a sweeping function recoverERC20 to handle mistakenly sent ERC20 tokens: function recoverERC20address token external onlyOwner returnsbool ifminAmountRewardTokentoken != 0 revert Errors.CannotRecoverToken; uint256 amount =...