Submitted by Spearbit, also found by 0xsanson, broccoli, cmichel, hyh, ming, OriDabush, Saw-mon_and_Natalie, and Yarpo
OrderValidator.sol#L228
OrderValidator.sol#L231
OrderValidator.sol#L237
OrderValidator.sol#L238
A partial orders fractions (numerator and denominator) can be reset to 0 due to a truncation. This can be used to craft malicious orders:
View full POC.
The following change would make the above POC fail:
A basic fix for this would involve adding the above checks for overflow / truncation and reverting in that case. However, we think the mechanism is still flawed in some respects and requires more changes to fully fix it. See a related issue: A malicious filler can fill a partial order in such a way that the rest cannot be filled by anyone that points out a related but a more fundamental issue with the mechanism.
0age (OpenSea) confirmed
0xleastwood (judge) commented:
0age (OpenSea) resolved:
