CVE-2021-33403

An integer overflow in the transfer function of a smart contract implementation for Lancer Token, an Ethereum ERC20 token, allows the owner to cause unexpected financial losses between two large accounts during a transaction...

CVE-2021-33403

The CVE concerns LNCToken (Lancer Token), an Ethereum ERC-20 token. The vulnerability is an integer overflow in the transfer function of the smart contract, which could allow the owner to cause unexpected financial losses between two large accounts during a transaction. The connected sources (inc...

redeemToken can fail for certain tokens

Handle cmichel Vulnerability details The SwappableYieldSource.redeemToken function transfers tokens from the contract back to the sender, however, it uses the ERC20.transferFromaddressthis, msg.sender, redeemableBalance function for this. Some deposit token implementations might fail as...

Deposits don't work with fee-on transfer tokens

Handle cmichel Vulnerability details There are ERC20 tokens that may make certain customizations to their ERC20 contracts. One type of these tokens is deflationary tokens that charge a certain fee for every transfer or transferFrom. Others are rebasing tokens that increase in value over time like...

Incorrect address check in transferERC20 can allow rugging

Handle 0xRajeev Vulnerability details Impact SwappableYieldSource.sol has a transferERC20 function callable only by the owner or asset manager to transfer out ERC20 tokens other than the yield source's tokens held by this contract. This is similar to the functions in ATokenYieldSource and...

Deposits don't work with fee-on transfer tokens

Handle cmichel Vulnerability details There are ERC20 tokens that may make certain customizations to their ERC20 contracts. Some tokens charge a certain fee for every transfer or transferFrom. Others types are rebasing tokens that increase in value over time like Aave's aTokens balanceOf changes...

ERC20 return values not checked

Handle cmichel Vulnerability details The ERC20.transfer and ERC20.transferFrom functions return a boolean value indicating success. This parameter needs to be checked for success. Some tokens do not revert if the transfer failed but return false instead. This is generally not an issue when the...

TransferHelper does not work with all ERC20 tokens

Handle cmichel Vulnerability details The TransferHelper.safeTransferFrom function will revert if tokens do not return a boolean because the interface ERC20.transfer function it uses indicates that this function always returns a boolean. Some tokens like USDT don't correctly implement the EIP20...

Incompatibility With Rebasing/Deflationary/Inflationary tokens

Handle 0xRajeev Vulnerability details Impact WildCredit allows the permissionless listing of any ERC20 assets/pairs to be used in the protocol. Some of these tokens could charge a fee, add a reward or rebase over time. However, the protocol does not have the required support to handle such tokens...

LendingPair._safeTransfer does not work with all ERC20 tokens

Handle cmichel Vulnerability details The LendingPair.safeTransfer function will revert if tokens do not return a boolean because the interface ERC20.transfer function it uses indicates that this function always returns a boolean. Some tokens like USDT don't correctly implement the EIP20 standard...

safeTransferFrom in TransferHelper is not safeTransferFrom

Handle jonah1005 Vulnerability details Impact A non standard erc20 token would always raise error when calling safeTransferFrom. If a user creates a USDT/DAI pool and deposit into the pool he would find out there's never a counterpart deposit. Proof of Concept TransferHelper does not uses SafeERC...

Gas griefing attack on the removeUserActiveBlocks function

Handle shw Vulnerability details Impact The consumed gas to remove a user's active block is proportional to the total number of array elements i.e., block numbers. However, the array size can be arbitrarily increased by an attacker with only paying gas fees, causing a gas griefing attack when the...

how to protect for weird erc20 tokens

Handle gpersoon Vulnerability details Impact The protocol only works as expected when the ERC20 tokens are well behaved. If rebasing tokens or malicious token contracts are used then unexpected results can happen. I don't see any code to restrict the tokens or verify the tokens. Proof of Concept...

Anyone can arbitrarily add router liquidity

Handle 0xRajeev Vulnerability details Impact The addLiquidity function takes a router address parameter whose liquidity is increased instead of assuming that router == msg.sender like done on removeLiquidity on this contract/chain by transferring the fund amount from router address to this contra...

receive and retrieve funds

Handle gpersoon Vulnerability details Impact When the function fulfill tries send ERC20 tokens to a receiving contract, it approve the callTo address to be able to retrieve the tokens. Later on on line 414 it calls the function "execute" of callTo, where this contract is supposed to retrieve the...

Return values of ERC20 transfer and transferFrom are unchecked

Handle shw Vulnerability details Impact In some contracts e.g., TracerPerpetualSwaps.sol, the return values of ERC20 transfer and transferFrom are not checked to be true, which could be false if the transferred tokens are not ERC20-compliant. In that case, the transfer fails without being noticed...

SafetyWithdraw ERC20 return values not checked

Handle cmichel Vulnerability details The ERC20.transfer and ERC20.transferFrom functions return a boolean value indicating success. This parameter should be checked for success. The SafetyWithdraw.withdrawERC20Token function does not check the return value: function withdrawERC20Token address...

erc20 transfers do not check the return value

Handle pauliax Vulnerability details Impact When transfering erc20 tokens, functions transfer and transferFrom are used. These functions return boolean to indicate if the action was sucessfull, however, none of the usages check the returned value: collateralToken.transferFrommsg.sender,...

Lack of return value check or use of SafeERC20 wrappers for token transfers

Handle 0xRajeev Vulnerability details Impact ERC20 tokens are specified to return a boolean value on token transfer and transferFrom. However, tokens may not adhere to the spec and return no value for success/failure. Checking the return values of ERC20 token transfers is therefore important to...

No check transferFrom() return value

Handle s1m0 Vulnerability details Impact The smart contract doesn't check the return value of token.transfer and token.transferFrom, some erc20 token might not revert in case of error but return false. In the TracerPerpetualSwaps:deposit and Insurance:deposit this would allow a user to deposit fo...