search

code-423n4 / 2021-11-unlock-findings

0 stars 0 forks source link

Long Revert Strings #36

Open code423n4 opened 2 years ago

code423n4 commented 2 years ago

Handle

Reigada

Vulnerability details

Impact

Shortening revert strings to fit in 32 bytes will decrease deployment time gas and will decrease runtime gas when the revert condition has been met.

Revert strings that are longer than 32 bytes require at least one additional mstore, along with additional overhead for computing memory offset, etc.

Proof of Concept

https://github.com/code-423n4/2021-11-unlock/blob/main/smart-contracts/contracts/mixins/MixinRoles.sol#L40 https://github.com/code-423n4/2021-11-unlock/blob/main/smart-contracts/contracts/mixins/MixinRoles.sol#L45 https://github.com/code-423n4/2021-11-unlock/blob/main/smart-contracts/contracts/Unlock.sol#L241 https://github.com/code-423n4/2021-11-unlock/blob/main/smart-contracts/contracts/Unlock.sol#L246 https://github.com/code-423n4/2021-11-unlock/blob/main/smart-contracts/contracts/UnlockDiscountTokenV2.sol#L27

Tools Used

Manual testing

Recommended Mitigation Steps

Shorten the revert strings to fit in 32 bytes.

Or in contracts using solc version 0.8.4 or greater use the Custom Errors feature.

0xleastwood commented 2 years ago

I think this is likely useful.