Liquidity Management
Gamma
DeFiFoundry
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Submission Details
Severity: low
Invalid

Missing Length Validation in runNextAction's Metadata

johnlaw

Data Validation, Denial of Service, Logic Issue

Summary

The runNextAction function accesses elements of the metadata array without verifying its length, triggering reverts when the array is smaller than expected.

Vulnerability Details

The runNextAction function decodes and uses metadata[0] and metadata[1] without ensuring that metadata.length meets the required minimum. This breaks the guarantee of reliable execution, because malformed or incomplete data from the keeper immediately triggers out-of-bounds errors. This scenario disrupts essential vault operations, including withdrawals and position adjustments.

Impact

Impact: Medium. The contract halts deposits, withdrawals, or position updates when malformed metadata is present.

Likelihood: Low. Only the keeper supplies metadata. A misconfigured keeper directly causes repeated transaction failures, resulting in denial of service for normal flows.

Tools Used

Manual Review

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;
​
import "forge-std/Test.sol";
import "../contracts/MockVault.sol";
​
// @notice demonstrates how passing an incomplete metadata array reverts the transaction in runNextAction.
contract VaultTest is Test {
MockVault vault;
​
function setUp() public {
vault = new MockVault();
}
​
function testRunNextActionRevertsOnIncompleteMetadata() public {
// MarketPrices struct
MockVault.MarketPrices memory prices = MockVault.MarketPrices({
indexTokenPrice: 1000e18,
shortTokenPrice: 500e18,
longTokenPrice: 1500e18
});
​
// "metadata" with only ONE element. This triggers an out-of-bounds revert.
bytes[] memory invalidMetadata = new bytes[](1);
invalidMetadata[0] = abi.encode(uint256(100));
​
// Expect a revert due to array out-of-bounds
vm.expectRevert();
vault.runNextAction(prices, invalidMetadata);
}
​
function testRunNextActionSucceedsWithValidMetadata() public {
// Setup valid data
MockVault.MarketPrices memory prices = MockVault.MarketPrices({
indexTokenPrice: 1000e18,
shortTokenPrice: 500e18,
longTokenPrice: 1500e18
});
​
// metadata with TWO elements, as the function decodes metadata[1] and metadata[0]
bytes[] memory validMetadata = new bytes[](2);
validMetadata[0] = abi.encode(uint256(100));
validMetadata[1] = abi.encode(MockVault.PROTOCOL.DEX, bytes("0xdeadbeef"));
​
// Should not revert now that metadata has sufficient length
vault.runNextAction(prices, validMetadata);
}
}
​

Recommendations

Implement strict length checks at the start of runNextAction:

require(metadata.length >= 2, "Insufficient metadata length");

This ensures that each index access is valid and prevents unintended reverts on incomplete metadata.

Updates

Lead Judging Commences

n0kto Lead Judge 5 months ago
Submission Judgement Published
Invalidated
Reason: Non-acceptable severity
Assigned finding tags:

Admin is trusted / Malicious keepers

Please read the CodeHawks documentation to know which submissions are valid. If you disagree, provide a coded PoC and explain the real likelihood and the detailed impact on the mainnet without any supposition (if, it could, etc) to prove your point. Keepers are added by the admin, there is no "malicious keeper" and if there is a problem in those keepers, that's out of scope. ReadMe and known issues states: " * System relies heavily on keeper for executing trades * Single keeper point of failure if not properly distributed * Malicious keeper could potentially front-run or delay transactions * Assume that Keeper will always have enough gas to execute transactions. There is a pay execution fee function, but the assumption should be that there's more than enough gas to cover transaction failures, retries, etc * There are two spot swap functionalies: (1) using GMX swap and (2) using Paraswap. We can assume that any swap failure will be retried until success. " " * Heavy dependency on GMX protocol functioning correctly * Owner can update GMX-related addresses * Changes in GMX protocol could impact system operations * We can assume that the GMX keeper won't misbehave, delay, or go offline. " "Issues related to GMX Keepers being DOS'd or losing functionality would be considered invalid."

Suppositions

There is no real proof, concrete root cause, specific impact, or enough details in those submissions. Examples include: "It could happen" without specifying when, "If this impossible case happens," "Unexpected behavior," etc. Make a Proof of Concept (PoC) using external functions and realistic parameters. Do not test only the internal function where you think you found something.

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