Swivel v3 contest - cccz's results

Lines of code

https://github.com/code-423n4/2022-07-swivel/blob/fd36ce96b46943026cb2dfcb76dfa3f884f51c18/Marketplace/MarketPlace.sol#L148-L149

Vulnerability details

Impact

In the MarketPlace contract, the unpaused modifier was not added to authRedeem function, which would make authRedeem function not controlled by paused.

Proof of Concept

https://github.com/code-423n4/2022-07-swivel/blob/fd36ce96b46943026cb2dfcb76dfa3f884f51c18/Marketplace/MarketPlace.sol#L148-L149

Tools Used

None

Recommended Mitigation Steps

-  function authRedeem(uint8 p, address u, uint256 m, address f, address t, uint256 a) public authorized(markets[p][u][m].zcToken) returns (uint256 underlyingAmount) {
+   function authRedeem(uint8 p, address u, uint256 m, address f, address t, uint256 a) public authorized(markets[p][u][m].zcToken) unpaused(p) returns (uint256 underlyingAmount) {

[Low-01] return value of 0 from ecrecover not checked

Impact

The solidity function ecrecover is used, however the error result of 0 is not checked for. See documentation: https://docs.soliditylang.org/en/v0.8.13/units-and-global-variables.html?highlight=ecrecover#mathematical-and-cryptographic-functions "recover the address associated with the public key from elliptic curve signature or return zero on error. "

Proof of Concept

https://github.com/code-423n4/2022-07-swivel/blob/fd36ce96b46943026cb2dfcb76dfa3f884f51c18/Swivel/Swivel.sol#L686-L698 https://github.com/code-423n4/2022-07-swivel/blob/fd36ce96b46943026cb2dfcb76dfa3f884f51c18/Swivel/Sig.sol#L20-L31 https://github.com/code-423n4/2022-07-swivel/blob/fd36ce96b46943026cb2dfcb76dfa3f884f51c18/Swivel/Sig.sol#L38-L42

Tools Used

None

Recommended Mitigation Steps

Verify that the result from ecrecover isn't 0

[Low-02] Unsupported fee-on-transfer tokens

Impact

Fee-on-transfer tokens are not supported in Swivel contracts For example, in the initiateZcTokenFillingVaultInitiate function, when the uToken is a fee-on-transfer token, the number of uTokens received by the contract will be less than a + fee, which will cause the contract to lose fees in the deposit function.

    uint256 fee = premiumFilled / feenominators[0];
    Safe.transferFrom(uToken, msg.sender, address(this), (a + fee));

    IMarketPlace mPlace = IMarketPlace(marketPlace);
    address cTokenAddr = mPlace.cTokenAddress(o.protocol, o.underlying, o.maturity);

    // perform the actual deposit type transaction, specific to a protocol
    if(!deposit(o.protocol, o.underlying, cTokenAddr, a)) { revert Exception(6, 0, 0, address(0), address(0)); }

Proof of Concept

https://github.com/code-423n4/2022-07-swivel/blob/main/Swivel/Swivel.sol

Tools Used

None

Recommended Mitigation Steps

Consider getting the received amount by calculating the difference of token balance (using balanceOf) before and after the _transferFrom.