Submission Details
Severity:
Replayable Signature Prone To Vote Manipulation
Summary
The signature on rankCandidatesBySig() can be replayed to get votes on the next s_voteNumber.
Vulnerability Details
The structHash used to construct the hash for signing lacks a nonce. This causes the voter signature to be replayable by anyone on the next vote (a different s_voteNumber) such that the voter loses a right to select a different set of candidates for the next president.
Impact
The voter cannot choose a fresh set of candidates.
Tools Used
Manual review, testing.
Recommendations
Add a voter nonce that will increment on every correct signature verification.
Updates
Lead Judging Commences
inallhonesty about 1 year ago
Submission Judgement Published Assigned finding tags:
Replay Attack - The same signature can be used over and over
Appeal created
evmninja
about 1 year ago
inallhonesty
about 1 year ago
inallhonesty about 1 year ago
Submission Judgement Published Assigned finding tags:
Replay Attack - The same signature can be used over and over
Rewards breakdown
nSLOC
140This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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