Rust Fund

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

Missing payout checks let a creator take deposits before campaign success

Description

  • A crowdfunding creator should withdraw only after the campaign reaches its goal and deadline conditions.

  • withdraw authenticates the creator but reads neither fund.goal nor fund.deadline, so the creator can take deposits immediately.

pub fn withdraw(ctx: Context<FundWithdraw>) -> Result<()> {
@> let amount = ctx.accounts.fund.amount_raised;
@> // no goal or deadline validation

Risk

Likelihood:

  • Any creator can call withdraw after the first contribution.

  • The path requires only the creator's normal signer account.

Impact:

  • A creator takes deposits from an unsuccessful campaign.

  • Contributors lose the expected refund protection.

Proof of Concept

The PoC creates a campaign with a 10,000-lamport goal and a future deadline, then contributes
only 5,000 lamports. Calling withdraw still pays all 5,000 lamports to the creator, which proves
the payout path does not enforce either campaign outcome condition.

fund.goal = 10_000;
fund.deadline = 1_000_000;
vulnerable_contribute(&mut fund, &mut contribution, 5_000);
assert_eq!(vulnerable_withdraw(&mut fund).unwrap(), 5_000);

Recommended Mitigation

Validate both conditions before calculating the payout: the deadline must be configured and
elapsed, and the raised amount must reach the goal. This keeps failed campaigns on the refund path
and permits creator withdrawal only for a completed successful campaign.

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