Submission Details
Severity:
Incorrect event emission in `RapBattle::_battle()`
Summary
The function RapBattle::_battle() can incorrectly emit the Battle event in a particular case.
Vulnerability Details
In the event, the defender wins if random is strictly less than his skill level.
emit Battle(msg.sender, _tokenId, random < defenderRapperSkill ? _defender : msg.sender);
But, after the event is emitted, the if block uses a <= to determine the winner.
if (random <= defenderRapperSkill) {
// Here defender wins
}
So, if random happens to be equal to the defender skill level, the event will emit the incorrect winner.
Impact
The users and the off-chain detection tools will register the incorrect winner.
Reccomended Mitigation
Simply change the chech condition inside the event to match the correct one used after it:
-emit Battle(msg.sender, _tokenId, random < defenderRapperSkill ? _defender : msg.sender);
+emit Battle(msg.sender, _tokenId, random <= defenderRapperSkill ? _defender : msg.sender);
Updates
Lead Judging Commences
inallhonesty over 1 year ago
Submission Judgement Published Assigned finding tags:
Contradictory battle result event
Rewards breakdown
nSLOC
201This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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