Tadle

Tadle
DeFi
30,000 USDC
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Submission Details
Severity: medium
Valid

protocol do not work with fee-on-transfer function

Summary

In multiple functions, it is assumed that number of token transfered equal to number of token received, which is not true with fee-on-transfer token

Vulnerability Details

In multiple functions, protocol assume that number of token transfered equal to number of token received. For example, function createOffer have assumption like that, it do not check pre-and-post balance if it is transfered enough when token have fee or not:

{
/// @dev transfer collateral from _msgSender() to capital pool
uint256 transferAmount = OfferLibraries.getDepositAmount(
params.offerType,
params.collateralRate,
params.amount,
true,
Math.Rounding.Ceil
);
ITokenManager tokenManager = tadleFactory.getTokenManager();
tokenManager.tillIn{value: msg.value}(
_msgSender(),
params.tokenAddress,
transferAmount,
false
);
}

Impact

Last user can not withdraw token normally, they have to deposit additional token to be able to withdraw them successfully.

Tools Used

Manual review

Recommendations

Allow user to deposit more token than they have to, and using pre-and-post balance checking to see if deposited token is enough or not, and transfer left over if they transfered too much.

Updates

Lead Judging Commences

0xnevi Lead Judge 11 months ago
Submission Judgement Published
Validated
Assigned finding tags:

finding-TokenManager-FOT-Rebasing

Valid medium, there are disruptions to the ability to take market actions. The following functions will be disrupted without the possibiliy of reaching settlement, since the respective offers cannot be created/listed regardless of mode when transferring collateral token required to the CapitalPool contract or when refunding token from user to capital pool during relisting. So withdrawal is not an issue - `createOffer()` - reverts [here](https://github.com/Cyfrin/2024-08-tadle/blob/04fd8634701697184a3f3a5558b41c109866e5f8/src/core/PreMarkets.sol#L96-L102) - `listOffer()` - reverts [here](https://github.com/Cyfrin/2024-08-tadle/blob/04fd8634701697184a3f3a5558b41c109866e5f8/src/core/PreMarkets.sol#L355-L362) - `relistOffer()` - reverts [here](https://github.com/Cyfrin/2024-08-tadle/blob/04fd8634701697184a3f3a5558b41c109866e5f8/src/core/PreMarkets.sol#L515-L521) - `createTaker()` - reverts [here](https://github.com/Cyfrin/2024-08-tadle/blob/04fd8634701697184a3f3a5558b41c109866e5f8/src/core/PreMarkets.sol#L831-L836) I believe medium severity is appropriate although the likelihood is high and impact is medium (only some level of disruption i.e. FOT tokens not supported and no funds at risk)

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