PaprController is vulnerable to reentrancy attacks

Lines of code Vulnerability details Impact Malicious users can steal PAPR tokens through reentrancy attacks. Proof of Concept Function PaprController.purchaseLiquidationAuctionNFT may trigger a reentrancy becase it calls ERC721.safeTransferFrom in NFTEDA.purchaseNFT:...

Collateral NFT deposited to a wrong address, when transferred directly to PaprController

Lines of code Vulnerability details Impact Users will lose collateral NFTs when they are transferred to PaprController by an approved address or an operator. Proof of Concept The PaprController allows users to deposit NFTs as collateral to borrow Papr tokens. One of the way of depositing is by...

Wrong implemention of ERC721TokenReceiver interface leads to incorrect collateral ownership and NFT loss

Lines of code Vulnerability details Impact To add a collateral, one could send the NFT directly to the contract, onERC721Received is called then to handle adding the collateral to the vault. However, if the user sends the NFT via an operator then the ownership of the collateral will be assigned t...

Some NFTs could be possibly stuck and can not be withdrawn when removing the collateral

Lines of code Vulnerability details Impact When adding a collateral, the protocol transfers the NFT from the user to the contract by calling ERC721's transferFrom, and when removing the collateral, safeTransferFrom is called to allow for onReceive hook to be triggered as intended by the protocol...

A BETTER APPROACH TO REVERTING CODE LINES ON _ADDCOLLATERALTOVAULT() AND _REMOVECOLLATERAL()

Lines of code Vulnerability details Impact In PaperControl.sol, callers would have to deal with function pre-maturely reverting upon encountering an element in collateralArr failing to pass the if statement in the function logic of addCollateralToVault and removeCollateral. The amount of gas wast...

if msg.sender != account, then msg.sender double pays in buyAndReduceDebt

Lines of code Vulnerability details Impact If msg.sender chooses to pay for some other account's debt, then he has to pay double. Proof of Concept msg.sender first has to pay the underlying tokens the paprToken from the swap goes to account controller then burns the papr tokens from msg.sender...

totalCollateralValue in maxDebt may not be calculated correctly everytime

Lines of code Vulnerability details Impact totalCollateralValue in maxDebt may not be calculated correctly sometimes which leads to questionable lending procedures. Proof of Concept Bob has 10 BAYC NFTs, one of which is an extremely rare one with a crown and a rainbow body, which costs about 150...

NFT operators of OpenZeppelin-based NFTs can issue debt

Lines of code Vulnerability details Description The Papr protocol allows NFT owners to issue debt against NFTs they deposit, denominated in papr. The solmate contracts that are used as imports for the project do not allow an operator on the NFT to participate in debt-creation; the ERC721 contract...

attacker can create un collateralized debt by reentrancy attack during _removeCollateral() by removing all collaterals and liquidating the last one which would set debt to zero. unfair liquidation can happen with reentrancy too

Lines of code Vulnerability details Impact Function removeCollateral removes collateral from msg.senders vault and code allows for onReceive hook to sell and repay debt before the debt check. during the hook function user can call other function of the PaprController contract, it's possible for...

PaprController.sol: reservoir oracle price equal to 0 allows bypassing NFT liquidations

Lines of code Vulnerability details Impact When there is a reservoir oracle message with the price of the NFT equal to zero, the debt of a vault will be reset in the PaprController.purchaseLiquidationAuctionNFT function when a NFT is bought in an auction. So the borrower can now withdraw all othe...

Misunderstanding operator with from

Lines of code Vulnerability details Author: rotcivegaf Impact The owner of the ERC721 token could approve an operator to manage his tokens With the misunderstanding of operator with from in the onERC721Received function the benefits of this function goes to the operator instead of the fromowner:...

Reentrancy attack allows to get loan for free

Lines of code Vulnerability details Impact Reentrancy attack allows to get loan for free when startLiquidationAuction is called on last collateral token. Proof of Concept When user has a bad debt, then anyone can start auction for his nft. To purchase token, liquidator can call...

incorrect message signer check in ecrecover() and no validation for oracleSigner which would cause all the unsigned messagess to be considered asvalid ones

Lines of code Vulnerability details Impact address oracleSigner has been used to verify signed messages by comparing the return value of ecrecover by oracleSigner. but the return value of ecrecover would be 0x0 and code doesn't check that return value is not 0x0. if owner set oracleSigner as 0x0 ...

PUNK does not conform to ERC721 standard hence safeTransferFrom from solmate does not work

Lines of code Vulnerability details Impact Since protocol's intended NFT target is PUNK currently, the protocol will be hugely affected. Proof of Concept Attempts to transfer the NFT is done in 2 places. 1. removeCollateral 2. purchaseNFT Firstly, this means that once a collateral is added to the...

Initial value of auction starter discount is set wrong

Lines of code Vulnerability details Impact The protocol offers a discount for auction starters when purchasing the liquidated NFT as an incentive for users to start an auction. I believe the intended discount should be 10%, but is currently implemented at 90%. 90% is too massive a discount for th...

Underlying With Non-Standard Decimals Not Supported

Lines of code Vulnerability details Impact Arithmetic operations are performed with the assumption that the token always has 18 decimals. Proof of Concept It would not be possible without using 18 decimal places of the base capital. Tools Used vscode Recommended Mitigation Steps Consider whether...

Signature mallebaility in underwritePriceForCollateral

Lines of code Vulnerability details Impact underwritePriceForCollateral has signature malleability as it doesn't check for a returned address of not 0. Value can be set to 0 oracleSigner Proof of Concept function underwritePriceForCollateralERC721 asset, PriceKind priceKind, OracleInfo memory...

Start an auction without an NFT

Lines of code Vulnerability details Impact Requires that the account being liquidated has more than one NFT in PaprController. When an operator calls purchaseLiquidationAuctionNFT the price variable is determined by a call to purchaseNFTAndUpdateVaultIfNeeded which calls purchaseNFT which calls...

Protocol faces truncation issue in some places due to solidity integer division

Lines of code Vulnerability details Impact UniswapOracleFundingRateController.sol : periodRatio , targetMarkRatio - less multiplier output than the actual value that is possible. EDAPrice.sol: again the final outcome affects the multiplier. Please refer the code link in POC. PaprController.sol:...

PaprController.onERC721Received() assigns collateral to operator's vault instead of the nft owner's one

Lines of code Vulnerability details Impact The collateral is assigned to the operator's vault because of a parameter mismatch. This impacts the ability of third parties to integrate the PaprController contract. You're not able to create an intermediary contract that adds collateral to a user's...

code doesn't check that the Uniswap pool is not exist and if attacker creates the uniswap pool before hand with calculatable papr address and underlying address and exact fee amount, then the deployment transaction would fail always

Lines of code Vulnerability details Impact attacker can perform DOS and prevent contract from getting deployed. the address of papr can be calculate by attacker before its deployment and the address of the underlyingUSDC and the fee is known, attacker can create uniswap pool before-hand and cause...

Liquidations force users into bigger debts

Lines of code Vulnerability details Impact User's uncovered debt increases when auction starts on their collateral token. The increased debt may be too big for a user and they might not be able to repay it, which forces them to wait for the auctioned token to be sold and accrue more debt due to t...

Insufficient Timestamp Validation for Signed Messages

Lines of code Vulnerability details Impact A message can be signed by the oracle for any future point in time, and it will be valid for 20 minutes. If messages with invalid timestamps pointing to the future get signed, there is no way of invalidating them. A compromised or malfunctioning oracle...

Stealing fund by applying reentrancy attack on removeCollateral, startLiquidationAuction, and purchaseLiquidationAuctionNFT

Lines of code Vulnerability details Impact By applying reentrancy attack involving the functions removeCollateral, startLiquidationAuction, and purchaseLiquidationAuctionNFT, an Attacker can steal large amount of fund. Proof of Concept Bob a malicious user deploys a contract to apply the attack...

Upgraded Q -> M from #22 [1671528877220]

Judge has assessed an item in Issue 22 as M risk. The relevant finding follows: minBidPrices is rounded down --- The text was updated successfully, but these errors were encountered: All reactions...

Upgraded Q -> M from #4 [1671527898955]

Judge has assessed an item in Issue 4 as M risk. The relevant finding follows: GroupBuy.contribute does not set pendingBalances for unused capital, leading to locked up money --- The text was updated successfully, but these errors were encountered: All reactions...

Borrowers may earn auction proceeds without filling the debt shortfall

Lines of code Vulnerability details Impact The proceeds from the collateral auctions will not be used to fill the debt shortfall, but be transferred directly to the borrower. Proof of Concept Assume N is an allowed NFT, B is a borrower, the vault V is vaultInfoBN: 1. B add two NFTsN-1 and N-2 as...

Upgraded Q -> M from #22 [1671528533640]

Judge has assessed an item in Issue 22 as M risk. The relevant finding follows: NC-2 Return values of approve not checked --- The text was updated successfully, but these errors were encountered: All reactions...

setFundingPeriod leads to Price control

Lines of code Vulnerability details Impact Attacker can use two different addresses to borrow from himself at different interest rates. Proof of Concept AS the papr interest rates and the papr trading price are in a constant feedback loop. Interest rates are programmatically updated on chain as a...

Upgraded Q -> M from #27 [1671522165760]

Judge has assessed an item in Issue 27 as M risk. The relevant finding follows: Dup of 45. The effect is severe enough IMO to warrant a med severity although I initially intepreted it as a spec mismatch. --- The text was updated successfully, but these errors were encountered: All reactions...

The patch is not sufficient: there is another insidious exploit that can cause the same critical consequences

Lines of code Vulnerability details Status Has been reported to and confirmed by Jeff ENS team Note to the Judge I am not sure whether I should label this as a newly-identified High or a mitigation hard error. The root cause of this issue seems as same as the original report, but this requires us...

sellQuote might lead to unexpected reverts when returning zero

Lines of code Vulnerability details Impact the implementation of sellQuote follows the logic of getAmountOut from Uniswap V2 Library. However it doesn't add +1 as the original implementation, this could make the function return zero and lead to reverts. Proof of Concept Tools Used Manual review...

PRICES CAN BE MANIPULATED WHEN LIQUIDITY IS VERY LOW

Lines of code Vulnerability details Impact Base and fractional token prices in the pool can be manipulated and set to values severely deviating from the originally intended price ratio right after the pool has been created. At this point, liquidity in the pool is deemed zero or exceptionally thin...

GroupBuy does not properly refund users

Lines of code Vulnerability details Impact On a successful purchase, users can call claim on the GroupBuy contract to mint and refund. The refunded amount is userContributions - summinReservePricesqty - pendingBalances. In case of the actual purchase price minReservePrices, the difference is not...

Merkle root of zero bypasses validation

Lines of code Vulnerability details Impact The merkle root validation happens with this require in validateTokenIds. If the merkle root is zero, this check is skipped. Proof of Concept This require validates that the merkle root is valid. This code is never reached if merkleRoot == bytes230 becau...

Early user can break the minting of LP Tokens

Lines of code Vulnerability details Impact The attack vector is the same as TOB-YEARN-003, where users may not receive liquidity tokens in exchange for their baseTokenAmount and fractionalTokenAmount deposited if the total baseTokenAmount has been manipulated through a large “donation”. In the...

Upgraded Q -> M from #201 [1671458492331]

Judge has assessed an item in Issue 201 as M risk. The relevant finding follows: Deposit function is not compatible with deflationary token The actual deposited amount might be lower than the specified depositAmount of the function parameter. This would lead to wrong interest rate calculations on...

Funds will be lost if the contract handling the refunds are unable to handle them at the moment

Lines of code Vulnerability details The return values of low-level calls are not checked Impact If the fund transfer results in a revert on the recipient's end, e.g. due to being paused, the code will continue on as if it had been successful, and the Ether will be lost. Proof of Concept Return...

unwrap function in Pair.sol can be exploited by a malicious user to exchange less expensive NFT's for more expensive ones in the pool

Lines of code Vulnerability details Impact nftRemove function burns lpTokens and releases baseTokenAmount and fractionalTokenAmount and then burns the fractionalTokenAmount to unwrap the NFT that is released back to the sender. At the time of unwrapping, code does not check if the tokenIds...

Orders may not be fillable due to missing approvals

Lines of code Vulnerability details Not all IERC20 implementations revert when there's a failure in approve. If one of these tokens returns false, there is no check for whether this has happened during the order listing validation, so it will only be detected when the order is attempted. Impact I...

Pair.sol has payable functions with no way of withdrawing that ether

Lines of code Vulnerability details Pair.sol has payable functions with no way of withdrawing that ether Summary Value is deposited on the contract using payable functions but later can't be taken out Impact Locked ether Proof of Concept Pair.adduint256,uint256,uint256 Pair.buyuint256,uint256...

Stealing liquidity provider's fund by manipulating the reserve

Lines of code Vulnerability details Impact An attacker can steal liquidity provider's fund by manipulating the reserve. During adding a liquidity, the amount of lpToken to be minted will be calculated in the function addQuote. function addQuoteuint256 baseTokenAmount, uint256 fractionalTokenAmoun...

Pair.sol can be manipulated to affect small liquidity providers.

Lines of code Vulnerability details Impact The first minter can manipulate the supply of LP tokens and baseToken-fractional ratio, hindering small liquidity providers from interacting with the pair. A malicious actor can mint 1wei of LP token from a new pair, then proceed to transfer baseToken to...

LP's ERC20 tokens cannot be rescued when owner closes the pair

Lines of code Vulnerability details Impact LP cannot be rescued when owner closes the pair. Aside from the NFT which can be salvaged through Pair.withdraw, the ERC20 token amounts cannot be rescued, resulting in fund loss. Proof of Concept In case of any malicious attempt to grief the protocol, t...

Surplus token after adding liquidity is not refunded to liquidity providers. LP might suffer front-running attack and lose funds.

Lines of code Vulnerability details Impact Function Pair.add receives base token and fractional token from liquidity providers and mint equivalent amount of LP token for them. The amount of LP token be minted is calculate in function addQuote function addQuoteuint256 baseTokenAmount, uint256...

Using safeTransferFrom() Functions But without Getting the Approval

Lines of code Vulnerability details Impact 2 safeTransferFrom calls are Used for ERC20 Token Line: 90, 172 using SafeTransferLib But without getting the Approval using safeApprove function. The Calls will always fail. 3 more safeTransferFrom calls are Used for ERC721 Tokens Line: 239, 259, 370...

Not supporting fee-on-transfer token as base token

Lines of code Vulnerability details Impact In Caviar protocol, all calculations in functions add, remove, buy, sell is done using token balance of Pair contract directly. In function add, it calculates and mints LP token to sender first before transferring baseToken in. function adduint256...

_transferFrom() in Pair contract doesn't update approval amounts when transferring user fractional tokens

Lines of code Vulnerability details Impact Contract Pair is and ERC20 token which represents user fractional token balance and it has all the features of the standard ERC20 tokens. function transferFrom has been written for transferring token but the logic isn't complete and it doesn't consider...

Incorrect rounding in buyQuote

Lines of code Vulnerability details The function buyQuote present in the Pair contract is used to calculate the amount of base tokens required to buy a given amount of fractional tokens. function buyQuoteuint256 outputAmount public view returns uint256 return outputAmount 1000 baseTokenReserves /...

Only one GroupBuy can ever use USDT or similar tokens with front-running approval protections

Lines of code Vulnerability details Calling approve without first calling approve0 if the current approval is non-zero will revert with some tokens, such as Tether USDT. While Tether is known to do this, it applies to other tokens as well, which are trying to protect against this attack vector...