Rust Fund
AI First Flight #9
Beginner FriendlyRust
EXP
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Submission Details
Severity: high
Valid

withdraw has no goal-reached or deadline check, letting the creator pull all contributions at any time — a rug-pull against contributors

sub99

withdraw has no goal or deadline gate, letting the creator rug-pull contributors at any time

Description

withdraw (lib.rs:90-105) pays the full amount_raised to the creator with no check that the funding goal was reached or that the deadline has passed; the FundWithdraw accounts struct only enforces has_one = creator (lib.rs:163). The creator can therefore withdraw the moment any contribution lands.

pub fn withdraw(ctx: Context<FundWithdraw>) -> Result<()> {
let amount = ctx.accounts.fund.amount_raised;
// @> no check: fund.amount_raised >= fund.goal OR deadline passed
**ctx.accounts.fund.to_account_info().try_borrow_mut_lamports()? =
ctx.accounts.fund.to_account_info().lamports()
.checked_sub(amount)
.ok_or(ProgramError::InsufficientFunds)?;
// creator credited `amount` :98-101
Ok(())
}

Risk

Likelihood:

Low — requires the creator to act maliciously (or carelessly) against their own campaign. But it needs no special conditions and no other actor; the creator already holds the only required signature.

Impact:

High. Contributors fund a goal-/deadline-gated crowdfund expecting release only on success, but the creator can sweep all contributed lamports at will before the goal is met and before refunds would otherwise become available — a complete rug-pull of contributor funds with no recourse.

Proof of Concept

One contribution, immediate creator withdraw with goal unmet.

await program.methods.fundCreate("camp", "d", new BN(1_000_000_000)).accounts({...}).rpc();
await contribute(victim, 50_000_000); // far below goal, no deadline reached
await program.methods.withdraw().accounts({ fund, creator }).rpc();
// succeeds: creator receives the 50_000_000 victim lamports

Recommended Mitigation

Gate withdraw on the goal being met and/or the deadline having passed.

pub fn withdraw(ctx: Context<FundWithdraw>) -> Result<()> {
let fund = &ctx.accounts.fund;
+ let now: u64 = Clock::get()?.unix_timestamp.try_into().unwrap();
+ require!(
+ fund.amount_raised >= fund.goal || (fund.deadline != 0 && fund.deadline <= now),
+ ErrorCode::UnauthorizedAccess
+ );
let amount = fund.amount_raised;
Updates

Lead Judging Commences

ai-first-flight-judge Lead Judge about 3 hours 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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