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";...

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...

Improper handling of large integer values

Description In create Fee function, improper handling of large integer values in mount field value. Proof of Concept POST /demonstration/Modules.php?modname=StudentBilling/StudentFees.php HTTP/1.1 Host: www.rosariosis.org Cookie: RosarioSIS=kja39eaq6q73envhk6eo8300vgumn2612c5huvue08vgh66faog1...

Fee-on-transfer tokens will mess up the internal accounting of the contract

Lines of code Vulnerability details Impact If the underlying token is a fee-on-transfer token, the amount of tokens that will be transferred to the contract isn't equal to the amount the supplyTokenTo tries to supply to the aave protocol, so the function will revert because the contract won't hav...

Inconsistent balance when supplying 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 transfer or transferFrom. Proof of Concept AaveV3YieldSource.solL237 Tools Used Manu...

Unsupported fee-on-transfer tokens

Low-01 Unsupported fee-on-transfer tokens Impact When underlyingAssetAddress is fee-on-transfer tokens, in the supplyTokenTo function, the actual amount of tokens received by the contract will be less than the depositAmount, so that the subsequent pool.supply function will fail to execute. Proof ...

Variables that should be bounded

Judge @GalloDaSballo has assessed the 8th item in QA Report 263 as Medium risk. The relevant finding follows: … The variable MasterChef.sol:43: uint16 depositFeeBP; // Deposit fee in basis points is never bounded, and UInt16.MaxValue is 65535 --- The text was updated successfully, but these error...

Shelter donations result in wrong internal balance if fee-on-transfer token is used

Judge @GalloDaSballo has assessed the 2nd Low-severity item in QA Report 66 as Medium risk. The relevant finding follows: … In case of a fee-on-transfer ERC20 token the savedTokens balance will not represent the actual balance of the contract: You can either disable the use of fee-on-transfer...

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 ...

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. If a contract does not allow for amounts to change after transfers, asset calculations will be incorrect. While the planned tokens to be used may not...

Unsupported fee-on-transfer tokens

Lines of code Vulnerability details Impact When tokenAddress is fee-on-transfer tokens, in the burnTokenFrom function, the actual amount of tokens received by the contract will be less than the amount. Proof of Concept Tools Used None Recommended Mitigation Steps Consider getting the received...

Protocol doesn't handle fee on transfer tokens

Lines of code Vulnerability details Impact Since the borrower is able to specify any asset token, it is possible that loans will be created with tokens that support fee on transfer. If a fee on transfer asset token is chosen, the protocol will contain a point of failure on the original lend call...

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...

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

Lines of code Vulnerability details Impact Wrong amount calculated for facilitatorTake Proof of Concept Arbitrary ERC20 tokens can be passed as loanAssetContractAddress. With a transfer, the received amount should be calculated every time to take into consideration a possible fee-on-transfer or...

Malicious owner can steal some funds from borrower

Lines of code Vulnerability details Impact Owner can make changes to the protocol with immediate effect. Malicious owner can watch for big lend in the mempool and front run it by maxing out originationFeeRate to 5%. The users, both lender and borrower, will still think that originationFeeRate is...

NFTLoanFacilitator: Unsupported fee-on-transfer tokens

Lines of code Vulnerability details Impact loanAssetContractAddress is specified by the user when the user creates a loan. When loanAssetContractAddress is fee-on-transfer tokens, in the lend function, the actual amount of tokens received by the contract will be less than the amount, so that the...

Lack of Limit on amount Allows Borrowers To Be Extorted For Interest Payments

Lines of code Vulnerability details Impact There is on limit on the upper bounds on the amount a lender may send to a borrower. Borrowers will then be forced to pay interest and facilitators fee on the full amount loaned. The impact for a borrower is that they may be forced to repay significantly...

Might not get desired min loan amount if _originationFeeRate changes

Lines of code Vulnerability details Impact Admins can update the origination fee by calling updateOriginationFeeRate. Note that a borrower does not receive their minLoanAmount set in createLoan, they only receive 1 - originationFee minLoanAmount, see lend. Therefore, they need to precalculate the...

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 ...

Fee-on-Transfer tokens aren’t supported

Lines of code Vulnerability details Details & Impact Tokens that are charge a fee on transfer will not work correctly if it is specified as a payment token for NFT mints or as a royalty asset. For NFT mints, the amount recorded by the NewPayment and NewWithdrawal events might not match the actual...