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

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-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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