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Submission Details
Severity: low
Invalid

Insufficient Input Validation in `CommunityVCS.sol

chainsentryaudits

Summary

An insufficient input validation vulnerability has been identified in the CommunityVCS.sol contract, specifically within the _deployVaults function. This flaw allows the deployment of an excessive number of vaults without any restrictions, potentially leading to high gas consumption and a Denial of Service (DoS) scenario. While the function is restricted to the contract owner, the lack of safeguards poses significant risks if the owner's credentials are compromised or if malicious intent arises.

Vulnerability Details

Vulnerability Overview

The _deployVaults function in CommunityVCS.sol lacks validation on the _numVaults parameter, allowing for the deployment of an arbitrary number of vaults. This unbounded input can be exploited to deploy a large number of vaults in a single transaction, leading to resource exhaustion and transaction failures.

Proof of Concept (PoC)

1. Setting an Excessive Vault Deployment Amount

function setVaultDeploymentParams(
uint128 _vaultDeploymentThreshold,
uint128 _vaultDeploymentAmount
) external onlyOwner {
vaultDeploymentThreshold = _vaultDeploymentThreshold;
vaultDeploymentAmount = _vaultDeploymentAmount;
emit SetVaultDeploymentParams(_vaultDeploymentThreshold, _vaultDeploymentAmount);
}

Explanation:
By invoking setVaultDeploymentParams, an attacker who gains access to the owner's account can set the _vaultDeploymentAmount to an extremely high value (e.g., 1000000). This parameter directly influences how many vaults are deployed during the upkeep process.

2. Triggering the Deployment of Excessive Vaults

function performUpkeep(bytes calldata) external {
if ((vaults.length - globalVaultState.depositIndex) >= vaultDeploymentThreshold)
revert VaultsAboveThreshold();
_deployVaults(vaultDeploymentAmount);
}

Explanation:
Calling performUpkeep after setting a high _vaultDeploymentAmount initiates the deployment of the specified number of vaults. Without input validation, this function will attempt to deploy all vaults in a single transaction, potentially exceeding the block's gas limit.

3. Observing Transaction Failure Due to Gas Limit Exceedance

Expected Outcome:
Attempting to deploy a vast number of vaults results in the transaction consuming more gas than the block limit allows. This causes the transaction to fail, effectively halting any further vault deployments and disrupting the staking platform's operations.

4. Attempting to Directly Add Vaults Without Restrictions

function addVaults(uint256 _numVaults) external onlyOwner {
_deployVaults(_numVaults);
}

Explanation:
Alternatively, an attacker can directly call addVaults with a high _numVaults value. Similar to the previous steps, this will lead to the deployment of an excessive number of vaults, resulting in high gas consumption and potential DoS.

5. Non-Owner Attempting to Deploy Vaults (Access Control Enforcement)

function testNonOwnerCannotDeployVaults() public {
vm.startPrank(nonOwner);
​
uint256 numVaults = 10;
​
// Expecting SenderNotAuthorized or similar revert
vm.expectRevert("Ownable: caller is not the owner");
communityVCS.addVaults(numVaults);
​
vm.stopPrank();
}

Explanation:
While the vulnerability is primarily exploitable by the owner, this test case ensures that non-owners cannot deploy vaults, reinforcing the importance of robust access control mechanisms.

Impact

The identified vulnerability poses several significant risks:

  • Denial of Service (DoS): Deploying an excessive number of vaults can exhaust the gas limit of a block, causing transactions to fail and disrupting the platform's normal operations.

  • Increased Gas Costs: Legitimate users may experience higher gas fees when interacting with the contract, leading to a degraded user experience.

  • Resource Exhaustion: The contract's storage and computational resources can be strained, potentially leading to performance issues and instability.

  • Trust Erosion: Repeated failures and operational disruptions can erode user trust in the platform's reliability and security.

Tools Used

  • Manual Review

  • Foundry

Recommendations

To mitigate the identified vulnerability and enhance the security posture of the CommunityVCS.sol contract, the following measures are recommended:

1. Implement Input Validation on _numVaults

Introduce a maximum limit on the number of vaults that can be deployed in a single transaction to prevent resource exhaustion.

uint256 public constant MAX_VAULTS_PER_CALL = 100;
​
function _deployVaults(uint256 _numVaults) internal {
require(_numVaults <= MAX_VAULTS_PER_CALL, "Exceeds maximum vaults per call");
bytes memory data = abi.encodeWithSignature(
"initialize(address,address,address,address)",
address(token),
address(this),
address(stakeController),
stakeController.getRewardVault()
);
for (uint256 i = 0; i < _numVaults; i++) {
_deployVault(data);
}
}

Explanation:
By setting a MAX_VAULTS_PER_CALL constant, the contract restricts the number of vaults that can be deployed in a single transaction, thereby preventing potential DoS attacks.

2. Enhance Access Control Mechanisms

While the function is already restricted to the owner, it's crucial to ensure that the owner's account is secure. Implementing multi-signature wallets or role-based access controls can further reduce the risk.

import "@openzeppelin/contracts/access/AccessControl.sol";
​
contract CommunityVCS is VaultControllerStrategy, AccessControl {
bytes32 public constant DEPLOYER_ROLE = keccak256("DEPLOYER_ROLE");
​
constructor() {
_setupRole(DEFAULT_ADMIN_ROLE, msg.sender);
_setupRole(DEPLOYER_ROLE, msg.sender);
}
​
modifier onlyDeployer() {
require(hasRole(DEPLOYER_ROLE, msg.sender), "Caller is not a deployer");
_;
}
​
function addVaults(uint256 _numVaults) external onlyDeployer {
_deployVaults(_numVaults);
}
}

Explanation:
By integrating OpenZeppelin's AccessControl, the contract can define specific roles, such as DEPLOYER_ROLE, to manage who can deploy vaults. This reduces reliance on a single owner account and enhances security.

3. Implement Batch Processing with Safe Limits

Allow vault deployments in smaller, manageable batches to ensure that each transaction remains within gas limits.

function deployVaultsInBatches(uint256 _totalVaults, uint256 _batchSize) external onlyOwner {
uint256 batches = _totalVaults / _batchSize;
for (uint256 i = 0; i < batches; i++) {
_deployVaults(_batchSize);
}
uint256 remaining = _totalVaults % _batchSize;
if (remaining > 0) {
_deployVaults(remaining);
}
}

Explanation:
By breaking down the total number of vaults into smaller batches, the contract ensures that each deployment remains within the gas limits, preventing transaction failures and maintaining operational stability.

4. Introduce Gas Consumption Safeguards

Incorporate mechanisms to estimate and limit the gas consumption of vault deployment functions.

function _deployVaults(uint256 _numVaults) internal {
require(_numVaults <= MAX_VAULTS_PER_CALL, "Exceeds maximum vaults per call");
uint256 gasLimit = 800000; // Example gas limit per deployment
for (uint256 i = 0; i < _numVaults; i++) {
require(gasleft() > gasLimit, "Insufficient gas for deployment");
_deployVault(data);
}
}

Explanation:
By setting a gasLimit and checking the remaining gas before each deployment, the contract can prevent transactions from running out of gas, ensuring smoother operations.

Updates

Lead Judging Commences

inallhonesty Lead Judge 12 months ago
Submission Judgement Published
Invalidated
Reason: Non-acceptable severity

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