Beatland Festival

AI First Flight #4
Beginner FriendlyFoundrySolidityNFT
EXP
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Submission Details
Severity: medium
Valid

configurePass resets passSupply to 0 allowing maxSupply bypass

Title: configurePass resets passSupply to 0 allowing maxSupply bypass
Severity: Medium
Impact: Total passes minted exceeds declared maxSupply after any reconfiguration.
Likelihood: Medium — requires organizer to reconfigure, but honest mistakes trigger it.
Reference Files: src/FestivalPass.sol:54-66

Description

configurePass unconditionally resets passSupply[passId] = 0, discarding the record of previously sold passes. After reconfiguration, buyPass allows minting up to the new maxSupply again, making the total circulating supply exceed the declared cap. The vulnerable code:

function configurePass(uint256 passId, uint256 price, uint256 maxSupply) external onlyOrganizer {
require(price > 0, "Price must be greater than 0");
require(maxSupply > 0, "Max supply must be greater than 0");
passPrice[passId] = price;
passMaxSupply[passId] = maxSupply;
passSupply[passId] = 0; // ← resets sold count to zero
}

If 50 GENERAL passes have been sold and the organizer reconfigures (e.g., to change price), the sold count resets to 0 — another 100 passes can be minted, totaling 150 against a max of 100.

Risk

Impact: Medium. The maxSupply cap becomes unenforceable across reconfigurations. Pass scarcity and economic value are undermined as more passes circulate than declared possible.
Likelihood: Medium. Requires organizer action, but honest reconfigurations (price changes, supply adjustments) trigger the bug unintentionally.
A festival with maxSupply=100 GENERAL passes could have 200+ circulating after two routine price adjustments, destroying the scarcity model for all pass holders.

Proof of Concept

function testSupplyResetBypassesMaxSupply() public {
vm.prank(organizer);
festivalPass.configurePass(1, 0.05 ether, 2); // maxSupply=2
// Sell both passes
vm.prank(user1); festivalPass.buyPass{value: 0.05 ether}(1);
vm.prank(user2); festivalPass.buyPass{value: 0.05 ether}(1);
// Supply at max — third purchase reverts
vm.prank(user3); vm.expectRevert("Max supply reached");
festivalPass.buyPass{value: 0.05 ether}(1);
// Organizer reconfigures — supply resets to 0!
vm.prank(organizer);
festivalPass.configurePass(1, 0.05 ether, 2);
// Now can mint another 2 passes despite maxSupply still being 2
vm.prank(user3); festivalPass.buyPass{value: 0.05 ether}(1);
// Total 4 passes minted against maxSupply=2
assertEq(festivalPass.balanceOf(user1, 1) + festivalPass.balanceOf(user2, 1)
+ festivalPass.balanceOf(user3, 1), 3);
assertEq(festivalPass.passMaxSupply(1), 2);
}

Three passes minted against a maxSupply of 2 after one reconfiguration — the cap is bypassed.

Recommended Mitigation

function configurePass(uint256 passId, uint256 price, uint256 maxSupply) external onlyOrganizer {
require(passId == GENERAL_PASS || passId == VIP_PASS || passId == BACKSTAGE_PASS, "Invalid pass ID");
require(price > 0, "Price must be greater than 0");
require(maxSupply > 0, "Max supply must be greater than 0");
require(maxSupply >= passSupply[passId], "Max supply below already sold");
passPrice[passId] = price;
passMaxSupply[passId] = maxSupply;
// REMOVED: passSupply[passId] = 0;
}

Removing the supply reset preserves the sold count, and the new require(maxSupply >= passSupply) check prevents lowering the cap below already-sold passes — maintaining the supply invariant across reconfigurations.

Updates

Lead Judging Commences

ai-first-flight-judge Lead Judge about 1 hour ago
Submission Judgement Published
Validated
Assigned finding tags:

[M-01] [H-1] Reseting the current pass supply to 0 in the FestivalPass::configurePass function allows users to bypass the max supply cap of a pass

# \[H-1] Reseting the current pass supply to `0` in the `FestivalPass::configurePass` function allows users to bypass the max supply cap of a pass ## Description: ```solidity function configurePass(uint256 passId, uint256 price, uint256 maxSupply) external onlyOrganizer { require(passId == GENERAL_PASS || passId == VIP_PASS || passId == BACKSTAGE_PASS, "Invalid pass ID"); require(price > 0, "Price must be greater than 0"); require(maxSupply > 0, "Max supply must be greater than 0"); passPrice[passId] = price; passMaxSupply[passId] = maxSupply; @> passSupply[passId] = 0; // Reset current supply } ``` If you reset `passSupply[passId]` to `0` in the `FestivalPass::configurePass` function after passes have been sold, the next buyer will be able to mint as if no passes have been sold. This allows the total minted passes to exceed `passMaxSupply`, which is a serious vulnerability (a supply cap bypass) ## Impact: * Supply caps become meaningless: The users can mint unlimited passes beyond the intended maximum supply * Pass scarcity and value are destroyed, affecting the economic model ## Proof of Concept: ```solidity function test_SupplyCapBypassVulnerability() public { // Step 1: Configure a pass with max supply of 2 vm.prank(organizer); festivalPass.configurePass(1, GENERAL_PRICE, 2); // Step 2: Buy 2 passes (reaching max supply) vm.prank(user1); festivalPass.buyPass{value: GENERAL_PRICE}(1); vm.prank(user2); festivalPass.buyPass{value: GENERAL_PRICE}(1); // Verify max supply reached assertEq(festivalPass.passSupply(1), 2); assertEq(festivalPass.passMaxSupply(1), 2); // Step 3: Try to buy another pass - should fail address user3 = makeAddr("user3"); vm.deal(user3, 10 ether); vm.prank(user3); vm.expectRevert("Max supply reached"); festivalPass.buyPass{value: GENERAL_PRICE}(1); // Step 4: VULNERABILITY - Organizer reconfigures the pass // This resets passSupply[1] to 0, bypassing the supply cap! vm.prank(organizer); festivalPass.configurePass(1, GENERAL_PRICE, 2); // Step 5: Now we can buy more passes even though max supply was already reached vm.prank(user3); festivalPass.buyPass{value: GENERAL_PRICE}(1); // Step 6: We can even buy more passes beyond the original max supply vm.deal(user4, 10 ether); vm.prank(user4); festivalPass.buyPass{value: GENERAL_PRICE}(1); // Step 7: Verify the vulnerability - total supply exceeds max supply assertEq(festivalPass.passSupply(1), 2); // Current supply counter assertEq(festivalPass.passMaxSupply(1), 2); // Max supply limit // But we actually have 4 passes minted in total! assertEq(festivalPass.balanceOf(user1, 1), 1); assertEq(festivalPass.balanceOf(user2, 1), 1); assertEq(festivalPass.balanceOf(user3, 1), 1); assertEq(festivalPass.balanceOf(user4, 1), 1); // Total minted: 4 passes, but max supply is only 2! uint256 totalMinted = festivalPass.balanceOf(user1, 1) + festivalPass.balanceOf(user2, 1) + festivalPass.balanceOf(user3, 1) + festivalPass.balanceOf(user4, 1); assertGt(totalMinted, festivalPass.passMaxSupply(1), "VULNERABILITY: Total minted exceeds max supply!"); } ``` ## Recommended Mitigation: The `passSupply` reset should be removed ```diff function configurePass(uint256 passId, uint256 price, uint256 maxSupply) external onlyOrganizer { require(passId == GENERAL_PASS || passId == VIP_PASS || passId == BACKSTAGE_PASS, "Invalid pass ID"); require(price > 0, "Price must be greater than 0"); require(maxSupply > 0, "Max supply must be greater than 0"); passPrice[passId] = price; passMaxSupply[passId] = maxSupply; - passSupply[passId] = 0; } ```

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