Liquidity Management
Gamma
DeFiFoundry
50,000 USDC
View results
Previous Next
Submission Details
Severity: low
Invalid

Improper ETH Transfer Handling in Critical Execution Fee Payments

elvin_a_block

Summary

The PerpetualVault._payExecutionFee function uses the deprecated .transfer() method for critical ETH transfers to the GmxProxy, creating a fragile payment pathway. While currently functional due to GmxProxy's minimal receive implementation, this pattern introduces upgrade risks and gas sensitivity. Future modifications to the proxy's ETH handling logic could exceed the 2300 gas limit imposed by .transfer(), potentially blocking core protocol operations like position management with fee payments.

Vulnerability Details

The PerpetualVault contract uses the deprecated .transfer() method for ETH transfers in its _payExecutionFee function (PerpetualVault.sol#L811). This method forwards a fixed 2300 gas stipend which creates a potential failure vector:

contract PerpetualVault is IPerpetualVault, Initializable, Ownable2StepUpgradeable, ReentrancyGuardUpgradeable {
function _payExecutionFee(uint256 depositId, bool isDeposit) internal {
uint256 minExecutionFee = getExecutionGasLimit(isDeposit) * tx.gasprice;
​
if (msg.value < minExecutionFee) {
revert Error.InsufficientAmount();
}
if (msg.value > 0) {
@> payable(address(gmxProxy)).transfer(msg.value);
depositInfo[depositId].executionFee = msg.value;
}
}
}

1.Gas Limitations:

  • The recipient contract (GmxProxy) currently implements an empty receive() function that works within 2300 gas

  • Any future modifications to GmxProxy that add receive function logic could exceed this gas limit

2.Upgrade Risks:

  • The GmxProxy contract is upgradeable through owner-controlled configuration changes

  • Future implementations might require more than 2300 gas for ETH handling logic

3.Protocol Impact:

  • Failed ETH transfers would block core functionality:

  • Order execution fee payments

  • GMX position management

  • Keeper operations

The current implementation creates a hidden upgrade trap where seemingly unrelated contract modifications could break core protocol functionality.

Impact

The use of .transfer() creates a medium-severity risk to protocol reliability:

  1. Core Function Failure:

    • Failed ETH transfers would block all GMX position operations

    • Keeper operations would become unreliable

  2. Upgrade-Induced Failures:

    • Future upgrades to GmxProxy that add receive function logic would break fee payments

    • Protocol becomes fragile to maintenance changes

  3. Financial Loss Vectors:

    • Stuck execution fees during high gas periods

    • Partial locking of protocol collateral during critical operations

  4. System-Wide Contagion:

    • Single failed transfer could cascade into:

      • Position liquidations

      • Funding fee accrual issues

      • User withdrawal failures

This vulnerability introduces unnecessary fragility in a critical payment pathway that affects the protocol's primary functionality.

Tools Used

Manual Review

Recommendations

Replace .transfer() with .call{} Pattern in PerpetualVault._payExecutionFee:

(bool success, ) = payable(address(gmxProxy)).call{value: msg.value}("");
if (!success) revert PayExecutionFeeFailed();
Updates

Lead Judging Commences

n0kto Lead Judge 8 months ago
Submission Judgement Published
Invalidated
Reason: Non-acceptable severity
Assigned finding tags:

Informational or Gas

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.

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."

Support

FAQs

Can't find an answer? Chat with us on Discord, Twitter or Linkedin.