A malicious user can create a vault that is actually empty

Lines of code Vulnerability details description A malicious user can call the createVault function to create a vault with an ERC20 token that returns false rather than revert on failed transfer. By specifying the tokenType parameter to be ERC721 the transferFrom function will be called rather tha...

Admin has ability to rugpull all tokens

Lines of code Vulnerability details Impact Currently it is possible for the admin to pull all tokens belonging to the Gravity bridge. In normal circumstances this is probably fine, but if the admin account were compromised this would lead to the bridge being drained of locked funds. Furthermore, ...

Gravity does not support ERC20 tokens with built-in fee

Lines of code Vulnerability details Impact Contract Gravity.sol 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...

Centralisation Risk: Admin can withdraw all ERC20 held in the bridge and all deployed CosmosERC20 tokens

Lines of code Vulnerability details Impact The function withdrawERC20 allows an admin to withdraw any ERC20 tokens help in the bridge. The impact of this is significant as the function deployERC20 will create a new CosmosERC20 token with MAXUINT256 supply minted to the Gravity smart contract. The...

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

Lines of code Vulnerability details Impact Wrong amount emitted in SendToCosmosEvent event Proof of Concept File: Gravity.sol 595: function sendToCosmos 596: address tokenContract, 597: bytes32 destination, 598: uint256 amount 599: public nonReentrant 600:...

ERC20 tokens with before/afterTokenTransfer hooks can be manipulated to cause submitBatch to fail

Lines of code Vulnerability details Impact Currently submitBatch processes a batch of Cosmos to Ethereum transactions. As part of this method ERC20 tokens are transferred to the desired destination from the Gravity bridge, as approved by the current validator set. For ERC20 tokens without a...

sendToCosmos doesn't consider the ERC20 transfer fee, resulting in incorrect amount of ERC20 token

Lines of code Vulnerability details Impact Some ERC tokens have a fee on each transfer. The protocol doesn’t handle the fee when transferring this kind of ERC20 tokens, leading to the inconsistent amount of token actually received in the contract. Validators on the Cudos will mint more tokens to...

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, sendToCosmos assumes that the received amount is the same as the transfer amount, and uses it to emit SendToCosmosEvent event. As a result, when bridging t...

Protocol unusable for some ERC20 tokens (bad tokens)

Lines of code Vulnerability details Impact Protocol unusable for some ERC20 tokens bad tokens PoC Some tokens don't correctly implement the EIP20 standard and their transfer/transferFrom return void The so called bad tokens. More info This makes the transaction revert when calling. Recommended Us...

Unchecked return value of transferFrom() leading to zero cost RewardFunding

Lines of code Vulnerability details Impact Due to unchecked return value of transferFrom in https://github.com/code-423n4/2022-05-factorydao/blob/main/contracts/PermissionlessBasicPoolFactory.solL144 , it is possible to fund a pool during creation without transferring tokens to use as rewardToken...

PermissionlessBasicPoolFactory's pools with fee on transfer tokens can be emptied by repetitive deposit-withdraws

Lines of code Vulnerability details Griefing attack is possible if pool deposit token is a fee on transfer ERC20 as deposit, withdraw atomic call sequence is allowed with pre-fee token quantity being accounted as deposit amount. Suppose F is a fee on transfer token and the pool with F as deposit...

Bogus deposits in Pools possible

Lines of code Vulnerability details Impact Bogus deposits in the Pools is possible by calling the function deposit with a malicious ERC20 token that always returns true whenever transferFrom is called. Tools Used Manual Inspection Recommended Mitigation Steps Create a whitelist of allowed ERC20...

Missing ERC20 return value check in MerkleVesting#withdraw

Lines of code Vulnerability details MerkleVestingwithdraw does not check the return value of the token withdrawal on line 173. If an ERC20 token returns false to indicate a failed transfer but does not revert, this transfer will silently fail but the withdrawal amount will still be deducted from...

Not all ERC20 tokens return boolean on transfer

Lines of code Vulnerability details Impact Some ERC20 tokens do not conform to the standard of returning a boolean when transfer is called. If one of these tokens is included as a reward token, the withdraw function will be irrevocably broken, and users won't be able to collect their reward or...

Pools and trees may be underfunded for fee-on-transfer tokens

Lines of code Vulnerability details Pools, vesting trees, and airdrop trees may all be created with fee-on-transfer tokens. When each of these entities is funded by a transfer in, their internal accounting assumes they receive the full amount transferred. However, they may actually receive fewer...

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

Lines of code Vulnerability details Impact Wrong bookkeeping, albeit limited to the concerned tree with a FoT Token Wrong amount emitted Proof of Concept contracts/MerkleDropFactory.sol: 77: requireIERC20merkleTree.tokenAddress.transferFrommsg.sender, addressthis, value, "ERC20 transfer failed";...

In MerkleVesting.sol::withdraw check return value of ERC20 transfer or use safeTransfer of OZ

Lines of code Vulnerability details Impact MerkleVesting.solL173 tree.tokenBalance -= currentWithdrawal; IERC20tree.tokenAddress.transferdestination, currentWithdrawal; In case of failed transfer here it do not check return value of transfer. it updates the tree balance without transfering the...

ERC20 transfers does not work on non-standard compliant tokens like USDT

Lines of code Vulnerability details Impact PermissionlessBasicPoolFactory.sol Consider this function: function deposituint poolId, uint amount external Pool storage pool = poolspoolId; requirepool.id == poolId, 'Uninitialized pool'; requireblock.timestamp pool.startTime, 'Cannot deposit before po...

Re-Entrancy Attack in PermissionlessBasicPoolFactory

Lines of code Vulnerability details Impact Since, the state change of pool.rewardFunding is taking place after the ERC20.transferFrom function, and since there is no whitelist of ERC20 tokens, therefore, it is very much possible that a malicious ERC20 contract can initiate a re-entrancy attack fr...

amount requires to be updated to contract balance increase (3)

Lines of code Vulnerability details Impact Every time transferFrom or transfer function in ERC20 standard is called there is a possibility that underlying smart contract did not transfer the exact amount entered. It is required to find out contract balance increase/decrease after the transfer. Th...