# ERC20 transfer / transferFrom with not checked return value

Lines of code Vulnerability details ERC20 transferFrom with not checked return value Impact Not every ERC20 token follows OpenZeppelin's recommendation. It's possible inside ERC20 standard that a transferFrom doesn't revert upon failure but returns false. Proof of Concept ERC20 transferFrom...

UNSAFE USAGE OF ERC20 TRANSFERFROM

Lines of code Vulnerability details Impact Ignores return value from L1GraphTokenGateway.finalizeInboundTransfer and L1GraphTokenGateway.outboundTransfer Not tracking values returned by token transfer from. finalizeInboundTransfer When escrow not approve for L1GraphTokenGateway or allowance is no...

USE OF SOLIDITY VERSION 0.8.14 WHICH HAS KNOWN ISSUES APPLICABLE TO Blur Exchange

Lines of code Vulnerability details Vulnerability details Vulnerability related to ‘Optimizer Bug Regarding Memory Side Effects of Inline Assembly’ ref : Blur Exchange inherits solidity contracts from openzeppelin and these uses inline assembly, and optimization is enabled while compiling...

The L1GraphTokenGateway does not work on non-standard compliant tokens like USDT

Lines of code Vulnerability details Vulnerability details The L1GraphTokenGateway function uses the standard IERC20 function for the transfer call and proceeds with a checkReturnCode function to handle non-standard compliant tokens that don't return a return value. However, this does not work as...

Use safetransfer/safetransferFrom instead of transfer/transferFrom in ERC20

Lines of code Vulnerability details Impact Its a good to checks the return value of token transfer using safetransfer or safetransferFrom on Openzeppelin to ensure the token revert when transfer failure. Failure to do so will cause silent failures of transfer and affect token accountng in contrac...

Missing ReEntrancy Guard to Withdraw function

Lines of code Vulnerability details Impact Missing ReEntrancy Guard to Withdraw function 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...

[NAZ-M3] Use safeTransfer()/safeTransferFrom() instead of transfer()/transferFrom()

Lines of code Vulnerability details Impact It is a good idea to add a require statement that checks the return value of ERC20 token transfers or to use something like OpenZeppelin’s safeTransfer/safeTransferFrom unless one is sure the given token reverts in case of a failure. Failure to do so wil...

ERC20.sol is susceptible to classic ERC20 approve functionality front-running exploit

Lines of code Vulnerability details Proof of concept The problem is perfectly described here The tldr; is that if you approved a person to spend 100 tokens and then you want to decrease his allowance to 50, if he spends his 100 tokens allowance before you set his allowance to 50 he will be able t...

Use safeTransferFrom() function instead of transferFrom()

Lines of code Vulnerability details Impact The transferFrom method is used in the contract PartyGovernanceNFT.sol, I however argue that this isn’t recommended because: OpenZeppelin’s documentation discourages the use of transferFrom, use safeTransferFrom whenever possible Given that any NFT can b...

# _safeMint() should be used rather than _mint() wherever possible

Lines of code Vulnerability details safeMint should be used rather than mint wherever possible Impact In Token.sol.sol, eventually it is called ERC721 mint. Calling mint this way does not ensure that the receiver of the NFT is able to accept them, making possible to lose them. safeMint should be...

transferFrom() failure in _safeTransferFrom() could drain the pair

Lines of code Vulnerability details Impact For some tokens, tokenCon.transferFrom could fail and return false but not revert. Some malicious user can abuse it the addLiquidity/addLiquidityCANTO function to perform failure transferFrom but still get the liquidity, and later remove liquidity to dra...

TRSRY.sol is susceptible to ERC20 approve functionality front-running exploit

Lines of code Vulnerability details Proof of concept The problem is perfectly described here The tldr; is that if you approved a person to spend 100 tokens and then you want to decrease his allowance to 50, if he spends his 100 tokens allowance before you set his allowance to 50 he will be able t...

ERC20 return value not checked and not compatible with tokens like USDT, OMG, etc

Lines of code Vulnerability details ERC20 return value not checked and not compatible with tokens like USDT, OMG, etc Detail The ERC20.transfer and ERC20.transferFrom functions return a boolean value indicating success. This parameter needs to be checked for success. Furthermore, some tokens like...

# ERC20 transfer / transferFrom with not checked return value

Lines of code Vulnerability details ERC20 transfer / transferFrom with not checked return value Impact Not every ERC20 token follows OpenZeppelin's recommendation. It's possible inside ERC20 standard that a transferFrom doesn't revert upon failure but returns false. Code doesn't check return...

Lack of check if token is a contract

Lines of code Vulnerability details Impact TransferHelper.sol and solmate won't check if the token is a contract or not. A hacker could set traps for non existing tokens to steal future funds from users. Proof of Concept The safeTransfer functions used in the contract are wrappers around the...

Openzeppelin contracts with critical and high vulnerabilities can be installed and used

Lines of code Vulnerability details Impact Currently, @openzeppelin/contracts and @openzeppelin/contracts-upgradeable versions are set as follows. "@openzeppelin/contracts": "^4.1.0", "@openzeppelin/contracts-upgradeable": "^4.1.0", For the specified version, there are some critical and high...

Update initializer modifier to prevent reentrancy during initialization

Lines of code Vulnerability details package.json L32-33 The solution uses: "@openzeppelin/contracts": "^4.1.0", "@openzeppelin/contracts-upgradeable": "^4.1.0", The current implementation of initialize function in both NounsDAOLogicV1.sol and NounsDAOLogicV2.sol are not using initializer modifier...

Voting signature malleability of EVM's ecrecover in castVoteBySig

Lines of code Vulnerability details Proof of Concept EVM's ecrecover is susceptible to signature malleability which allows replay attacks, but that is mitigated here by doing receipt.hasVoted = true;. However, if any of the application logic changes, it might make signature malleability a risk fo...

The repository uses versions of OpenZeppelin libraries with critical severity vulnerabilities

Lines of code Vulnerability details Proof of Concept The project uses 4.1.0 for both @openzeppelin/contracts and @openzeppelin/contracts-upgradeable but OpenZeppelin has flagged them as versions with critical severity vulnerability: GHSA-5vp3-v4hc-gx76 Also in those versions you have this...

Storage collision between proxy and logic v2

Lines of code Vulnerability details The lack of using EIP1967 proposal can lead to a storage collision on variables when implementing proxy-implementation pattern. More details can be found here; Impact Since the project implementing proxies with logic and implementation pattern where they share...