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Created 10 Feb 2026Updated 10 Feb 2026
Creator TipJar (Solidity Reentrancy)
A small onchain tip-jar dApp lets creators withdraw tips, but a payout flow is vulnerable to reentrancy.
solidity320 pts35 min
Overview
The Creator TipJar dApp lets fans tip creators onchain and lets creators withdraw their accumulated tips.
Main workflow:
tipCreator(address creator)receives ETH and credits that creator.withdrawTips(uint256 amount)sends ETH to the caller.
A bug bounty report says a malicious creator contract can drain more ETH than its recorded balance.
Your task: inspect the payout path, identify the exact vulnerable line, and describe how to fix it using secure Solidity patterns.
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creator-tipjar-reentrancy-solidity
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contracts/ReentrancyAttacker.solsol