in VeAssetDepositor and Booster contract don't set safeApprove() to 0 first and that token uses OpenZeppelin’s ERC20 implementation

Lines of code Vulnerability details Impact OpenZeppelin’s implementation of safeApprove won't work if approved amount is not set to 0. so the logics will fail if code don't set it 0 first. Both VeToken and VE3Token use OpenZeppelin’s ERC20 implementation and VeAssetDepositor and Booster calls...

deposit function of VeAssetDepositor.sol will be failed if stakeAddress is set.

Lines of code Vulnerability details Impact Wrong contract variable is used, so transaction cannot be executed. Proof of Concept This line is trying to call ERC20 function from minter contract. The minter is not ERC20 token, and does not have safeApprove function. So this will revert transaction...

Non standard token transfers will fail in the protocol

Lines of code Vulnerability details Impact In TokenTransferrer.sol the performERC20Transfer function handles the transfer of ERC20 tokens in the protocol. It uses the ERC20transferFromsignature constant inherited from TokenTransferrerConstants.sol. The problem is that tokens that don’t correctly...

Anyone can add Gauge reward tokens and cause DoS

Lines of code Vulnerability details Impact The Gauge.notifyRewardAmount function does not have any access restriction. Anyone an attacker can frontrun and call this function to add arbitrary even malicious gauge reward tokens up to MAXREWARDTOKENS = 16. An attacker is able to frontrun and add 16...

Bribe.sol Tokens with fee on transfer are not supported

Lines of code Vulnerability details There are ERC20 tokens that charge fee for every transfer or transferFrom. In the current implementation, Bribe.solnotifyRewardAmount assumes that the received amount is the same as the transfer amount, and uses it to calculate reward amounts. As a result, in...

notifyRewardAmount() griefing attack by adding MAX_REWARD_TOKENS

Lines of code Vulnerability details function notifyRewardAmountaddress token, uint amount external lock requireamount 0; if !isRewardtoken requirerewards.length Recommendation Consid...

Anyone can add Bribe reward tokens and cause DoS

Lines of code Vulnerability details Impact The Bribe.notifyRewardAmount function does not have any access restriction. Anyone an attacker can frontrun and call this function to add arbitrary even malicious reward tokens up to MAXREWARDTOKENS = 16. An attacker is able to frontrun and add 16 fake...

Consistently check account balance before and after transfers for Fee-On-Transfer discrepancies

Lines of code Vulnerability details As arbitrary ERC20 tokens can be passed, the amount here should be calculated every time to take into consideration a possible fee-on-transfer or deflation. Also, it's a good practice for the future of the solution. Affected code: contracts/contracts/Bribe.sol:...

QA Report

Impact RubiconRouter.swapEntireBalance is supposed to buy at least buyamtmin of Y output tokens by using the caller's entire X input token balance. The problem is that instead of passing the buyamtmin minus the fee to swap, the code uses the caller's X token balance, maxAmount. This means the cal...

Consistently check account balance before and after transfers for Fee-On-Transfer discrepancies

Lines of code Vulnerability details As arbitrary ERC20 tokens can be passed, the amount here should be calculated every time to take into consideration a possible fee-on-transfer or deflation. Also, it's a good practice for the future of the solution. Affected code:...

ExtraRewardsDistributor deposits don’t work with fee-on transfer tokens

Lines of code Vulnerability details Impact 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 safetransfer or safetransferFrom . Proof of Concept The ExtraRewardsDistributor’s...

Griefing attack by transferring aTokens to the contract

Originally part of a QA report by Tadashi 69 Griefing attack by transferring aTokens to the contract Summary: tokenToShares uses the following formula for computing the total shares of an user: return supply == 0 ? tokens : tokens.mulsupply.divaToken.balanceOfaddressthis; An attacker wishing to...

Possible lost msg.value

Lines of code Vulnerability details Impact Possible lost value in depositCollateral function call Proof of Concept In call depositCollateral can will send value and the asset can be an ERC20!= address0, if LidoVault and ConvexCurveLPVault contract receive this call the fouds will lost Also in...

YearnTokenAdapter's wrap can become stuck as it uses one step approval for an arbitrary underlying

Lines of code Vulnerability details Some tokens do not allow for approval of positive amount when allowance is positive already to handle approval race condition, most known example is USDT. This can cause the function to stuck whenever a combination of such a token and leftover approval be met...

ConvexCurveLPVault's _transferYield can become stuck with zero reward transfer

Lines of code Vulnerability details Now there are no checks for the amounts to be transferred via transferYield and processTreasury. As reward token list is external and an arbitrary token can end up there, in the case when such token doesn't allow for zero amount transfers, the reward retrieval...

TokenType mismatch with true type can be exploited to steal funds

Lines of code Vulnerability details A vault can be created for different TokenTypes, namely ERC20 and ERC721. These tokens have different logic, so a user needs to pass the type of the underlying token when creating a vault. At the end of createVault the user's tokens are pulled into the contract...

“No Revert on Failure“ tokens can be stolen from the contract by disguising them as NFTs.

Lines of code Vulnerability details Impact If a user creates a vault with an ERC20 token with the following two properties: 1. There’s a way to make transferFrom fail to transfer tokens without reverting e.g. some tokens like ZRX return false on failure instead of reverting. 2. fransferFromfrom,...

Fee-on-transfer / rebasing ERC20 cannot be used as underlying

Lines of code Vulnerability details Some ERC20 tokens may have fee-on-transfer or change balance without owner intervention. If these tokens are used as underlying in the protocol they can be lost. Proof of concept Alice creates a vault with a token that has a 1% fee on transfer. She sends...

Cally does not support ERC20 tokens with built-in fee

Lines of code Vulnerability details Impact Contract Cally does not properly handle ERC20 tokens that charge fee on their transfers. Implementation of such a tokens does not transfer exact amount provided to transfer but part of it is charged as a fee, burned or used in some other way. This leads ...

Use ERC721.safertransferFrom instead of ERC721.transferFrom when you send out NFT

Lines of code Vulnerability details Impact Buyers can accidentally lose their NFT if they send to incorrect address. Proof of Concept When the buyer decide to call exercise the NFT is transfered using transferFrom. This is risky because if the destination msg.sender is a contract and it is unable...