TeamVesting

Scope

• Contract: TeamVesting.sol

• Version: v1

• Framework: OpenZeppelin Contracts v5

Executive Summary

The TeamVesting contract has been audited for security vulnerabilities and coding best practices. The contract implements a linear vesting schedule for Lendefi team members with appropriate access controls that allow team members to manage their vested tokens while giving the DAO (via timelock) the ability to cancel vesting if necessary. The contract demonstrates solid security practices with well-documented functions and clear separation of concerns. No critical vulnerabilities were identified.

Key Findings

Severity	Number of Findings
Critical	0
High	0
Medium	0
Low	2
Informational	2

Risk Assessment

Access Control ✅

The contract implements a well-designed access control system:

• Uses Ownable2Step with the beneficiary (team member) as the owner

  • Two-step ownership transfer protects against accidental transfer mistakes

  • Beneficiary can claim their vested tokens directly via the release() function

• Uses onlyTimelock modifier to restrict cancellation to the timelock controller

  • Timelock address is stored as an immutable variable, preventing modification post-deployment

  • This provides the DAO with necessary control to terminate vesting if needed

Vesting Implementation ✅

The contract implements a secure linear vesting mechanism:

function _vestingSchedule(uint256 totalAllocation, uint64 timestamp) internal view virtual returns (uint256) {
    if (timestamp < start()) {
        return 0;
    } else if (timestamp >= end()) {
        return totalAllocation;
    }
    return (totalAllocation * (timestamp - start())) / duration();
}

Key security features:

• Immutable parameters for start time, duration, token address, and timelock

• Proper accounting of released tokens via _tokensReleased

• Secure token transfers using SafeERC20

• Appropriate boundary checks for timestamps

Cancellation Security ✅

The contract allows only the timelock controller to cancel the vesting and reclaim unvested tokens:

function cancelContract() external nonReentrant onlyTimelock returns (uint256 remainder) {
    // Release vested tokens to beneficiary first
    // Return unvested tokens to timelock
}

The implementation correctly:

• Releases any vested tokens to the beneficiary before cancellation

• Only returns the remaining (unvested) tokens to the timelock

• Uses nonReentrant modifier to prevent reentrancy attacks

• Checks for non-zero amounts before emitting events and performing transfers

Reentrancy Protection ✅

The contract uses OpenZeppelin's ReentrancyGuard for all state-changing external functions:

• release() and cancelContract() both use the nonReentrant modifier

• The contract follows the checks-effects-interactions pattern

Detailed Findings

Low Severity

1. No Start Time Validation

   The constructor does not validate that the start timestamp is reasonable:

   _start = startTimestamp;

   While this allows flexibility for different vesting scenarios, it could lead to user errors if a very distant future or very far past timestamp is used accidentally.

   Recommendation: Consider adding validation to ensure startTimestamp is within a reasonable range.

2. No Duration Minimum

   The contract accepts any non-zero duration, potentially allowing extremely short vesting periods:

   _duration = durationSeconds;

   Recommendation: Consider adding a reasonable minimum duration (e.g., 30 days) to ensure the vesting serves its intended purpose.

Informational

1. Release Function Can Be Called By Anyone

   The release() function can be called by anyone, not just the owner:

   function release() public virtual nonReentrant {
       // ...
   }

   This is a common pattern and not a vulnerability since tokens are always sent to the owner, but should be noted that external parties can trigger token releases.

2. No Recovery Mechanism for Other Tokens

   If tokens other than the vesting token are accidentally sent to the contract, there is no mechanism to recover them. This is a common limitation in many vesting contracts but could potentially lead to locked funds.

Conclusion

The TeamVesting contract implements a secure linear vesting mechanism with an ownership model that appropriately balances team member control and DAO oversight. The design choice to make the beneficiary the owner (using Ownable2Step) while giving the timelock the ability to cancel vesting is well-aligned with the contract's purpose.

The contract successfully implements several security best practices:

1. ✅ Two-step ownership transfers

2. ✅ Immutable critical parameters

3. ✅ Reentrancy protection

4. ✅ Safe token transfers using SafeERC20

5. ✅ Proper event emissions with zero-value checks

6. ✅ Clear access controls

7. ✅ Comprehensive NatSpec documentation

The identified issues are relatively minor and do not pose significant security risks to the contract's operation. The contract is suitable for its intended purpose of managing token vesting for Lendefi DAO team members.