FeeSplitter: totalWeights can be set to 0 by onlyOwner

[code423n4]

Handle

GiveMeTestEther

Vulnerability details

Impact

The storage variable totalWeights can be set 0 by onlyOwner and therefore we would have a division by zero in the function "_computeShareCount"
https://github.com/code-423n4/2021-11-nested/blob/5d113967cdf7c9ee29802e1ecb176c656386fe9b/contracts/FeeSplitter.sol#L268

Proof of Concept

-Assumption we have one shareholder with weight S1 > 0 and royaltiesWeight > 0.
-With the function updateShareholder the onlyOwner sets the S1 of our shareholder to 0.
- updateShareholder: https://github.com/code-423n4/2021-11-nested/blob/5d113967cdf7c9ee29802e1ecb176c656386fe9b/contracts/FeeSplitter.sol#L166
- require(_totalWeights > 0, "FeeSplitter: TOTAL_WEIGHTS_ZERO") condition is met because _totalWeights is the sum of all shareholder weights + royaltiesWeight, and royaltiesWeight is > 0

• With the function setRoyaltiesWeight the onlyOwner sets the royaltiesWeight to 0.
  • setRoyaltiesWeight: https://github.com/code-423n4/2021-11-nested/blob/5d113967cdf7c9ee29802e1ecb176c656386fe9b/contracts/FeeSplitter.sol#L94
• => setRoyaltiesWeight is 0 and totalWeights is 0

Tools Used

Manual Analysis

Recommended Mitigation Steps

At the end of the function setRoyaltiesWeight check for 0 weight with a require: require(totalWeights > 0, "FeeSplitter: TOTAL_WEIGHTS_ZERO");
https://github.com/code-423n4/2021-11-nested/blob/5d113967cdf7c9ee29802e1ecb176c656386fe9b/contracts/FeeSplitter.sol#L94