Beanstalk: The Finale
Beanstalk
DeFiHardhatFoundry
250,000 USDC
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Submission Details
Severity: high
Invalid

withdrawDeposit in SiloFacet and otehr functions using not safe Library LibTransfer

barneyetherguardian

Summary

LibTransfer use safeTransfer without any checks.

In scenario where whitelisted by bean governance ERC20 token is upgradeable and can change safeTransfer function to malicious implementation with return bomb or just reenter funtion as callback in loop might be very dangerous for protocol.

Can lost much of funds.

LibTransfer

Vulnerability Details

function like

withdrawDeposit

https://github.com/Cyfrin/2024-05-beanstalk-the-finale/blob/4e0ad0b964f74a1b4880114f4dd5b339bc69cd3e/protocol/contracts/beanstalk/silo/SiloFacet/SiloFacet.sol#L83

uses LibTransfer.sendToken

https://github.com/Cyfrin/2024-05-beanstalk-the-finale/blob/4e0ad0b964f74a1b4880114f4dd5b339bc69cd3e/protocol/contracts/libraries/Token/LibTransfer.sol#L68C1-L73C1

function sendToken(IERC20 token, uint256 amount, address recipient, To mode) internal {
if (amount == 0) return;
if (mode == To.INTERNAL) LibBalance.increaseInternalBalance(recipient, token, amount);
else token.safeTransfer(recipient, amount);
}

doesn't check safeTransfer

Impact

Can lost much funds and criple by reentry, siphoning or return bomb atack whole protocol.

Tools Used

slither, hardhat , code analyze

Recommendations

in LibTransfer.sol change implementation of sendToken to something like that:

1) check if success and check i there is no additional data in return or something like that data.length == 0

function sendToken(IERC20 token, uint256 amount, address recipient, To mode) internal {
if (amount == 0) return;
if (mode == To.INTERNAL) {
LibBalance.increaseInternalBalance(recipient, token, amount);
} else {
// Safe transfer call with manual return value check
(bool success, bytes memory data) = address(token).call(
abi.encodeWithSelector(token.safeTransfer.selector, recipient, amount)
);
require(success && (data.length == 0 || abi.decode(data, (bool))), "Token transfer failed");
}
}
Updates

Lead Judging Commences

inallhonesty Lead Judge about 1 year ago
Submission Judgement Published
Invalidated
Reason: Lack of quality

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