First Flight #5: Santa's List

Summary

Santa can change his mind even after checking his list twice, which isn't fair :(
(Also if his key is exposed people on the nice list can be unfairly removed)

Vulnerability Details

A user who has been extra good this year, and who santa has already checked twice, can lose their extra good status if santas key is exposed or hacked.
It is debatable that for this contract, this should not be allowed, and once the second check has been done on someone, they should be locked in with their status. Otherwise it is not a "Check Twice" function but rather just "Change Status".

Impact

A user can unfairly be taken off of the nice list even if they were extra nice.

Tools Used

Manual Review

Recommendations

Add a mapping (address=>bool) isCheckedTwice and set it to true once second check has been completed.