Rust Fund

AI First Flight #9
Beginner FriendlyRust
EXP
View results
Submission Details
Severity: high
Valid

Creator can withdraw all the amount raised at any time

Root + Impact
https://github.com/CodeHawks-Contests/2025-03-rustfund/blob/b5dd7b0ec01471667ae3a02520701aae405ac857/programs/rustfund/src/lib.rs#L90

The withdraw function does not check if the deadline is already reached and if the goal is met before allow the creator to withdraw

Description

  • The creator should beable to withdraw the amount raised only if the goal is met by the deadline but the current system doesnt perform any of the necessary checks and allows the creator withdraw at any time

// Root cause in the codebase with @> marks to highlight the relevant section

Risk

Likelihood:

  • High, Can occur at any time after a contribution has been made

Impact:

  • Creator can easily rug pull and contributors can never get refunds

Proof of Concept

it("Allows Creator Withdraw funds at any time", async () => {
console.log("Withdrawing...");
const fund = await program.account.fund.fetch(fundPDA);
const creatorBalanceBefore = await provider.connection.getBalance(creator.publicKey);
console.log("creatorBalanceBefore", creatorBalanceBefore);
console.log("fundBalanceBefore", await provider.connection.getBalance(fundPDA));
await program.methods
.withdraw()
.accounts({
fund: fundPDA,
creator: creator.publicKey,
systemProgram: anchor.web3.SystemProgram.programId,
})
.rpc();
const creatorBalanceAfter = await provider.connection.getBalance(creator.publicKey);
console.log("creatorBalanceAfter", creatorBalanceAfter);
console.log("fundBalanceAfter", await provider.connection.getBalance(fundPDA));
});

Recommended Mitigation

In the withdraw function, always check if the goal is met and the deadline has passed before allowing withdrawal

Updates

Lead Judging Commences

ai-first-flight-judge Lead Judge 1 day ago
Submission Judgement Published
Validated
Assigned finding tags:

[H-01] No check for if campaign reached deadline before withdraw

## Description A Malicious creator can withdraw funds before the campaign's deadline. ## Vulnerability Details There is no check in withdraw if the campaign ended before the creator can withdraw funds. ```Rust pub fn withdraw(ctx: Context<FundWithdraw>) -> Result<()> { let amount = ctx.accounts.fund.amount_raised; **ctx.accounts.fund.to_account_info().try_borrow_mut_lamports()? = ctx.accounts.fund.to_account_info().lamports() .checked_sub(amount) .ok_or(ProgramError::InsufficientFunds)?; **ctx.accounts.creator.to_account_info().try_borrow_mut_lamports()? = ctx.accounts.creator.to_account_info().lamports() .checked_add(amount) .ok_or(ErrorCode::CalculationOverflow)?; Ok(()) } ``` ## Impact A Malicious creator can withdraw all the campaign funds before deadline which is against the intended logic of the program. ## Recommendations Add check for if campaign as reached deadline before a creator can withdraw ```Rust pub fn withdraw(ctx: Context<FundWithdraw>) -> Result<()> { //add this if ctx.accounts.fund.deadline != 0 && ctx.accounts.fund.deadline > Clock::get().unwrap().unix_timestamp.try_into().unwrap() { return Err(ErrorCode::DeadlineNotReached.into()); } //stops here let amount = ctx.accounts.fund.amount_raised; **ctx.accounts.fund.to_account_info().try_borrow_mut_lamports()? = ctx.accounts.fund.to_account_info().lamports() .checked_sub(amount) .ok_or(ProgramError::InsufficientFunds)?; **ctx.accounts.creator.to_account_info().try_borrow_mut_lamports()? = ctx.accounts.creator.to_account_info().lamports() .checked_add(amount) .ok_or(ErrorCode::CalculationOverflow)?; Ok(()) } ``` ## POC keep everything in `./tests/rustfund.rs` up on to `Contribute to fund` test, then add the below: ```TypeScript it("Creator withdraws funds when deadline is not reached", async () => { const creatorBalanceBefore = await provider.connection.getBalance(creator.publicKey); const fund = await program.account.fund.fetch(fundPDA); await new Promise(resolve => setTimeout(resolve, 150)); //default 15000 console.log("goal", fund.goal.toNumber()); console.log("fundBalance", await provider.connection.getBalance(fundPDA)); console.log("creatorBalanceBefore", await provider.connection.getBalance(creator.publicKey)); await program.methods .withdraw() .accounts({ fund: fundPDA, creator: creator.publicKey, systemProgram: anchor.web3.SystemProgram.programId, }) .rpc(); const creatorBalanceAfter = await provider.connection.getBalance(creator.publicKey); console.log("creatorBalanceAfter", creatorBalanceAfter); console.log("fundBalanceAfter", await provider.connection.getBalance(fundPDA)); }); ``` this outputs: ```Python goal 1000000000 fundBalance 537590960 creatorBalanceBefore 499999999460946370 creatorBalanceAfter 499999999960941400 fundBalanceAfter 37590960 ✔ Creator withdraws funds when deadline is not reached (398ms) ``` We can notice that the creator withdraws funds from the campaign before the deadline.

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