Rust Fund

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

`withdraw` does not check that the funding goal was met — the creator can withdraw a failed campaign's funds

Description

In a crowdfunding model the creator should receive the raised funds only if the campaign succeeds — i.e. fund.amount_raised >= fund.goal. If the goal is not met, contributors are entitled to refunds and the creator must not be able to take the money. RustFund's withdraw performs no goal check: it transfers amount_raised to the creator regardless of whether the goal was reached.

pub fn withdraw(ctx: Context<FundWithdraw>) -> Result<()> {
let amount = ctx.accounts.fund.amount_raised;
// @> no check that fund.amount_raised >= fund.goal
**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(())
}

The fund.goal field is set at creation but never consulted by withdraw (or anywhere else).

Risk

Likelihood: High

  • Any creator of an under-funded campaign can withdraw; nothing checks the goal. It needs only the creator's signature.

Impact: High

  • The creator can drain a failed campaign's contributions, pocketing money that should have been refundable to contributors. The core all-or-nothing crowdfunding guarantee is broken, and contributors lose funds they should be able to reclaim.

Proof of Concept

fund_create(ctx, "camp", "desc", 100_000_000_000)?; // goal = 100 SOL
contribute(ctx_a, 1_000_000_000)?; // only 1 SOL raised (goal NOT met)
withdraw(ctx_creator)?; // @> succeeds despite amount_raised < goal

The withdrawal succeeds even though amount_raised (1 SOL) is far below goal (100 SOL).

Recommended Mitigation

Require the goal to be met before allowing withdrawal:

require!(fund.amount_raised >= fund.goal, ErrorCode::GoalNotReached);
Updates

Lead Judging Commences

ai-first-flight-judge Lead Judge 7 days ago
Submission Judgement Published
Validated
Assigned finding tags:

[H-02] H-01. Creators Can Withdraw Funds Without Meeting Campaign Goals

# H-01. Creators Can Withdraw Funds Without Meeting Campaign Goals **Severity:** High\ **Category:** Fund Management / Economic Security Violation ## Description The `withdraw` function in the RustFund contract allows creators to prematurely withdraw funds without verifying if the campaign goal was successfully met. ## Vulnerability Details In the current RustFund implementation (`lib.rs`), the `withdraw` instruction lacks logic to verify that the campaign's `amount_raised` is equal to or greater than the `goal`. Consequently, creators can freely withdraw user-contributed funds even when fundraising objectives haven't been met, undermining the core economic guarantees of the platform. **Vulnerable Component:** - File: `lib.rs` - Function: `withdraw` - Struct: `Fund` ## Impact - Creators can prematurely drain user-contributed funds. - Contributors permanently lose the ability to receive refunds if the creator withdraws early. - Severely damages user trust and undermines the economic integrity of the RustFund platform. ## Proof of Concept (PoC) ```js // Create fund with 5 SOL goal await program.methods .fundCreate(FUND_NAME, "Test fund", new anchor.BN(5 * LAMPORTS_PER_SOL)) .accounts({ fund, creator: creator.publicKey, systemProgram: SystemProgram.programId, }) .signers([creator]) .rpc(); // Contribute only 2 SOL (below goal) await program.methods .contribute(new anchor.BN(2 * LAMPORTS_PER_SOL)) .accounts({ fund, contributor: contributor.publicKey, contribution, systemProgram: SystemProgram.programId, }) .signers([contributor]) .rpc(); // Set deadline to past await program.methods .setDeadline(new anchor.BN(Math.floor(Date.now() / 1000) - 86400)) .accounts({ fund, creator: creator.publicKey }) .signers([creator]) .rpc(); // Attempt withdrawal (should fail but succeeds) await program.methods .withdraw() .accounts({ fund, creator: creator.publicKey, systemProgram: SystemProgram.programId, }) .signers([creator]) .rpc(); /* OUTPUT: Fund goal: 5 SOL Contributed amount: 2 SOL Withdrawal succeeded despite not meeting goal Fund balance after withdrawal: 0.00089088 SOL (rent only) */ ``` ## Recommendations Add conditional logic to the `withdraw` function to ensure the campaign has reached its fundraising goal before allowing withdrawals: ```diff pub fn withdraw(ctx: Context<FundWithdraw>) -> Result<()> { let fund = &mut ctx.accounts.fund; + require!(fund.amount_raised >= fund.goal, ErrorCode::GoalNotMet); let amount = 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(()) } ``` Also define the new error clearly: ```diff #[error_code] pub enum ErrorCode { // existing errors... + #[msg("Campaign goal not met")] + GoalNotMet, } ```

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