Not calling approve(0) before setting a new approval causes the call to revert when used with Tether (USDT)

Lines of code Vulnerability details Some tokens do not implement the ERC20 standard properly but are still accepted by most code that accepts ERC20 tokens. For example Tether USDT's approve function will revert if the current approval is not zero, to protect against front-running changes of...

Code credits fee-on-transfer tokens for amount stated, not amount transferred

Lines of code Vulnerability details Some ERC20 tokens, such as Tether USDT, allow for charging a fee any time transfer or transferFrom is called. Impact The code miscalculates whether the loan has been fully paid or bought out because it relies on the value of amounts passed in rather than the...

Unauthorized ERC20 changes

Lines of code Vulnerability details Impact It's possible by anyone to change the name and symbol of CToken. Proof of Concept The require was made in reverse condition, it checks that the sender must be different than admin in order to be able to change the name and symbol requiremsg.sender !=...

Re-entrace danger in PCVDeposit

Lines of code Vulnerability details Impact A malicious contract can empty all the system if he get ETH with the function withdrawETH. The onlyPCVController call this function and send ETH to the malicious contract, and then the malicious can use delegatecall and pretend to be onlyPCVController, a...

Tokens with fee on transfer are not supported

Lines of code Vulnerability details There are ERC20 tokens that charge fee for every transfer / transferFrom. Vault.soladdValue assumes that the received amount is the same as the transfer amount, and uses it to calculate attributions, balance amounts, etc. But, the actual transferred amount can ...

Borrowers lose funds if they call repayAndCloseLoan instead of closeLoan

Lines of code Vulnerability details Impact The repayAndCloseLoan function does not revert if there has not been a lender for a loan matched with lend. Users should use closeLoan in this case but the contract should disallow calling repayAndCloseLoan because users can lose funds. It performs a...

Token Transfers Are Not Handled Correctly

Lines of code Vulnerability details Impact The transfer function is used to send royalty assets to the splitter contract and its recipients. If the vault operates on non-standard ERC20 tokens, its possible for transfers to not revert upon failure. Similarly, transferFrom is used to pull funds fro...

CoreCollection's token transfer can be disabled

Lines of code Vulnerability details Impact When royaltyAsset is an ERC20 that doesn't allow zero amount transfers, the following griefing attack is possible, entirely disabling CoreCollection token transfer by precision degradation as both reward distribution and vault balance can be manipulated...

Ineffective Handling of FoT or Rebasing Tokens

Lines of code Vulnerability details Impact Certain ERC20 tokens may change user's balances over time positively or negatively or charge a fee when a transfer is called FoT tokens. The accounting of these tokens is not handled by RoyaltyVault.sol or Splitter.sol and may result in tokens being stuc...

Result of transfer not checked

Lines of code Vulnerability details Impact A call to transfer is done without checking the results. For certain ERC20 tokens, if insufficient tokens are present, no revert occurs but a result of "false" is returned. So it's important and also a best practice to check this. Note that, in almost al...

Improper Token Balance Check on swap()

Lines of code Vulnerability details Improper Token Balance Check on swap Description The swap can be separated in 2 paths, swap native to ERC20, or swap ERC20 to native. The contract performs a fromAssetId balance check before calling swap, mean that the attacker could periodically check for ERC2...

If contract holds balance of any ERC20 token, any user can take it

Lines of code Vulnerability details Impact If the LiFiDiamond contract ends up holding any ERC20 token, any user is able to perform a swap from the held asset to another asset, and the swap will use the contracts' funds as input instead of their own. The result is that a user can take all of the...

Missing input validation could lead to loss of fund

Lines of code Vulnerability details Impact A faulty input in GenericSwapFacet.swapTokensGeneric could cause funds to get stuck in the contract. In addition, tokens left in the LiFi contract can be retrieved by anyone see issue: ERC20 withdrawals can be frontrun, leading to loss of fund. Proof of...

Incorrect strike price displayed in name/symbol of qToken

Lines of code Vulnerability details Impact slice in options/QTokenStringUtils.sol cut a string into stringstart:end However, while fetching bytes, it uses bytessstart+1 instead of bytessstart+i. This causes the return string to be composed of sstartend-start. The result of this function is then...

Fee-on-transfer/deflationary tokens cause problems

Lines of code Vulnerability details Some ERC20 tokens, such as USDT, allow for charging a fee any time transfer or transferFrom is called. If a contract does not allow for amounts to change after transfers, subsequent transfer operations based on the original amount will revert due to the contrac...

Missing allowlist checks on tokens in CrossAnchorBridge could cause loss of funds

Lines of code Vulnerability details Impact The CrossAnchorBridge contract accepts any ERC20 token and transfers them to the wormhole bridge. There were allowlist checks on the tokens before, but they were commented out in this version for the audit. If a user transfers, for example, non-supported...

Deposit Box Does Not Account for Fee On Transfer Tokens Causing the Bridge To Absorb the Fees

Lines of code Vulnerability details Impact The function DepositBoxERC20.depositERC20 does not account for FoT Fee on Transfer tokens. FoT tokens charge a fee when transfer or transferFrom is called and it is subtracted from amount so the receiving address will receive less than amount of tokens...

Fee-on-transfer/deflationary tokens cause problems

Lines of code Vulnerability details Some ERC20 tokens, such as Tether USDT, allow for charging a fee any time transfer or transferFrom is called. If a contract does not allow for amounts to change after transfers, subsequent transfer operations based on the original amount will revert due to the...

transferredAmount on mainnet can be drained if a malicious account can mint more tokens on Schain

Lines of code Vulnerability details Impact Anyone on Schain that is able to mint more tokens, other than the mint action from postMessage in tokenManagerERC20 by bridging tokens over, can potentially drain the locked tokens in transferredAmount in depositBoxERC20 on mainnet by calling exit with t...

Centralisation Risk: Admin Role of TokenManagerEth can Rug Pull All Eth from the Bridge

Lines of code Vulnerability details Impact There is a Centralisation risk of the bridge where the DEFAULTADMINROLE of TokenManagerEth.sol is able to modify the ERC20 token on the SChain to any arbitrary address. This would allow the admin role to change the address to one where they have infinite...