owner can brick unwrapping by setting unwrap devisor = 0

[c4-bot-9]

Lines of code

https://github.com/code-423n4/2023-11-shellprotocol/blob/485de7383cdf88284ee6bcf2926fb7c19e9fb257/src/ocean/Ocean.sol#L196

Vulnerability details

Impact

The protocol does not handle when Ocean.changeUnwrapFee() sets unwrapFeeDivisor = 0 gracefully.

When setting unwrapFeeDevisor = 0, the function Ocean._calculateUnwrapFee() will revert due to a division by 0.

This function is used in the callstacks related to:

• Ocean._erc1155Unwrap()
• Ocean._erc20Unwrap()
• Ocean._etherUnwrap()

Note that users will still be able to wrap tokens as the contract only accumulates dust from rounding on these transactions.

• Ocean._erc721Wrap
• Ocean._erc1155Wrap
• Ocean._erc20Wrap

Recommended Mitigation Steps

Either prevent changeUnwrapFee from setting a value of 0 or gracefully handle a zero in callstacks where the _calculateUnwrapFee() function is used.

Assessed type

Invalid Validation

[c4-pre-sort]

raymondfam marked the issue as insufficient quality report

[c4-pre-sort]

raymondfam marked the issue as duplicate of #27

[c4-judge]

0xA5DF marked the issue as unsatisfactory: Invalid