Submitted by sorrynotsorry
VTVLVesting.sol has _createClaimUnchecked function to create the claims internally while validating parameters with the users allocations.
However, _releaseIntervalSecs is not validated comparing to users  _linearVestAmount and _startTimestamp _endTimestamp.
Theoretically, _linearVestAmount should be equal to ((_endTimestamp - _startTimestamp) * _releaseIntervalSecs) so the _releaseIntervalSecs = _linearVestAmount / ((_endTimestamp - _startTimestamp).
But this check was never done.
If the _releaseIntervalSecs is validated either to a higher or to a lower amount, it will create unfair distributions amongst the users during withdrawals due to being higher/lower than it should be. And also it may end up with the last withdrawals can be reverted due to the calculation board not matching.
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The _releaseIntervalSecs should be validated comparing to users  _linearVestAmount and _startTimestamp _endTimestamp.
0xean (judge) decreased severity to Medium and commented:
lawrencehui (VTVL) acknowledged, but disagreed with severity and commented:
