Rust Fund

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

003_CRITICAL_withdraw-ownership-bypass

Description

The withdraw function lacks a critical validation check: it does not verify that the campaign has reached its funding goal (fund.amount_raised >= fund.goal). This omission allows a campaign creator to withdraw the collected funds at any time, even if the campaign is failing, blatantly violating the crowdfunding logic.

Risk

  • Severity: Critical

  • Likelihood: High

  • Impact: Critical

Impact Details:

  1. Funds Theft: Creators can rug-pull backers by withdrawing funds immediately, bypassing the success condition.

  2. Broken Contract: The core "all-or-nothing" promise of the crowdfunding platform is negated.

Proof of Concept

The following test scenario demonstrates a creator withdrawing funds from a campaign that has arguably failed (raised < goal).

#[tokio::test]
async fn test_premature_withdrawal() {
// ... Setup code (create fund with Goal = 1000) ...
// 1. Contribute 500 (Less than goal)
// [Call contribute instruction]
// 2. Creator attempts to withdraw
let transaction = Transaction::new_with_payer(
&[instruction::withdraw(
&program_id,
&creator.pubkey(), // Creator signs
)],
Some(&payer.pubkey()),
);
// 3. Assert Success (Should FAIL if secure)
let result = banks_client.process_transaction(transaction).await;
assert!(result.is_ok(), "Vulnerability confirmed: Creator withdrew funds despite missing goal.");
}

Recommended Mitigation Steps

Implement a check to ensure the goal is met before allowing withdrawal.

Detailed Changes

pub fn withdraw(ctx: Context<Withdraw>) -> Result<()> {
let fund = &mut ctx.accounts.fund;
let creator = &ctx.accounts.creator;
+ // Verify goal is reached
+ if fund.amount_raised < fund.goal {
+ return Err(ErrorCode::GoalNotReached.into());
+ }
let amount = fund.amount_raised;
fund.amount_raised = 0;
// Transfer logic...
Ok(())
}
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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