CollarSwap
Smart Contract Audit Report
Audit Summary
CollarSwap is building a new Decentralized Exchange and a platform where users can stake tokens and earn rewards.
For this audit, we reviewed the following contracts on the Ethereum Mainnet:
- CollarSwapERC20, CollarSwapPair, and CollarSwapFactory contracts at 0xe15b4d98af270161219d2349f160dfdee7abce40.
- CollarSwapRouter contract at 0xc67f50f4a93147268d45f5cd7e444ec94eb046c7.
- CollarStake contract at 0x23f4f88ff6604114bea9f6faf60d69a4a833cd4a.
- CollarFlexStake contract at 0x6030804493bf035ffaaffdb4118412737a48348e.
Audit Findings
All findings have been resolved.
Date: October 7th, 2022.
Updated: November 29th, 2022 to include the project team's CollarFlexStake contract.
Updated: February 3rd, 2023 to reflect the CollarFlexStake contract's Mainnet address.Finding #1 - CollarStake - High (Resolved)
Description: The owner can call the emergenecy() function and withdraw any staked tokens from the contract.
Risk/Impact: The team can withdraw any user's staked tokens at any time.function emergenecy(address token, address to, uint256 amount)external onlyOwner{ if(token == address(0x0)){ require(payable(to).send(amount),"transaction failed"); } else { IERC20(token).transfer(to, amount); } emit emergencySafe(to, token, amount); }
Recommendation: The contract should include logic that disallows the owner from being able to withdraw tokens that have been assigned as staking tokens.
Resolution: The team has removed the above function from the contract.
Finding #2 - CollarStake - Medium (Resolved)
Description: Although the stake(), unstake(), updateMaxTokenStake(), updatePoolAPYpercentage(), updateCoolDownTime(), updateCollarToken(), poolCreation(), and poolStatus() functions use thewhenNotPaused
modifier, a function does not exist to pause/unpause the contract.
Risk/Impact: The contract can never be paused by the team.
Recommendation: The team should add a function that allows them to pause/unpause the contract or should remove the modifier from the above functions for additional gas savings on each call.
Resolution: The team has added a pause() and unPause() function to the contract.
Contracts Overview
CollarSwapERC20 Contract:CollarSwapPair Contract:
- This contract contains the core functionality of the CollarSwap LP token ($Collar-LP) maintained by the CollarSwapPair contract.
- The contract supports ERC-712 signed messages which users can use to grant allowances via a signed message, allowing for gasless approvals.
- The contract complies with the ERC-20 standard.
CollarSwapFactory Contract:
- This contract supports the core functionality of the Liquidity Pool token, which contains the logic behind LP minting, burning, and swapping between the assets in the liquidity pool.
- Anyone can use the mint function to mint an amount of LP tokens proportional to the number of tokens in the contract that are not accounted for in the reserves.
- Anyone can use the burn function to burn any LP tokens in the contract and receive an amount of asset tokens proportional to the represented value of the LP tokens.
- Anyone can use the swap function to transfer out an amount of the assets from the pool such that the new K value is at least as much as the current K value.
- The swap function supports flash swaps which allows anyone to use a contract to borrow any amount of any asset, as long as the borrowed amount of each asset is returned within the call.
- There is a fee taken on all swaps; the fee remains in the liquidity pool and is proportionally allocated among all LP token holders.
- Anyone can use the skim function to transfer out any excess tokens that are not accounted for in the reserve amounts.
- Alternatively, anyone can use the sync function to include any excess tokens in the reserve amounts so that they cannot be removed.
CollarSwapRouter Contract:
- This contract is used to deploy new CollarSwapPair contracts specifying two underlying token assets.
- Anyone can create any pair at any time, as long as the pair has not been created yet.
- Only one CollarSwapPair contract can exist for any combination of two token assets.
- The "FeeTo Setter" address can set the "FeeTo" and the "FeeTo Setter" addresses to any address at any time.
CollarStake Contract:
- This contract is used to interact with any CollarSwapPair liquidity pool contract created by the CollarSwapFactory contract.
- Upon adding liquidity, the user specifies the desired minimum amount of each token in the pair to add to the liquidity pool; the user is minted CollarSwapPair LP tokens representing their share of ownership of the liquidity pool.
- Upon removing liquidity, the user specifies the desired minimum amount of each token asset to receive from the liquidity pool; the user's LP tokens are burnt in the process.
- Liquidity removals support ERC-712 permits which allow the user to approve the Router to spend the user's LP tokens in a gasless manner.
- Liquidity adds and removals support fee-on-transfer tokens.
- Anyone can use this contract to swap one token asset for any other supported asset along a user-specified path of token assets.
CollarFlexStake contract:
- Users can stake tokens into various pools set by the team by specifying a number of tokens and a number of staking days.
- The specified number of tokens must not exceed the stake limit set by the team.
- The reward end time for each stake will be set to the number of specified days.
- Users can claim rewards after staking at any time. The number of tokens sent to the user is calculated based on the user's total number of staked tokens, the difference between the reward end time and the user's last claim, and the APY percentage assigned to the pool.
- Users can unstake from each pool once the reward end time assigned to the stake has passed. Rewards are automatically claimed upon unstaking.
- After a user successfully unstakes, they can withdraw their staked amount once the cool-down period of the contract has passed.
- The team must exercise caution when assigning the staking token to avoid using fee-on-transfer tokens. If a fee-on-transfer token is assigned, the team must ensure that the proper addresses are excluded from fees.
- The team must also exercise caution when assigning the staking token and the reward token to avoid using ERC-777 compliant tokens.
- The owner can use this contract to transfer reward tokens from their wallet to the contract at any time.
- The owner can pause/unpause the contract at any time which disables all staking, unstaking, withdrawing, and claiming.
- The owner can activate/deactivate any created pool at any time.
- The owner can update the reward token address at any time.
- The owner can update the cool-down period to any value at any time.
- The owner can update the APY percentage assigned to each pool to any value at any time.
- The owner can set the maximum stake limit to any value at any time.
- Users can stake tokens into various pools set by the team by specifying a number of tokens.
- The specified number of tokens must not exceed the stake limit set by the team.
- The reward end time for each stake will automatically be set to 1 year.
- Users can claim rewards after staking at any time. The number of tokens sent to the user is calculated based on the user's total number of staked tokens, the difference between the reward end time and the user's last claim, and the APY percentage assigned to the pool.
- Users can withdraw their staked tokens at any time. Rewards are automatically claimed on withdrawals.
- The team must exercise caution when assigning the staking token to avoid using fee-on-transfer tokens. If a fee-on-transfer token is assigned, the team must ensure that the proper addresses are excluded from fees.
- The team must also exercise caution when assigning the staking token and the reward token to avoid using ERC-777 compliant tokens.
- The owner can use this contract to transfer reward tokens from their wallet to the contract at any time.
- The owner can pause/unpause the contract at any time which disables all staking, withdrawing, and claiming.
- The owner can activate/deactivate any created pool at any time.
- The owner can update the reward token address at any time.
- The owner can update the cool-down period to any value at any time.
- The owner can update the APY percentage assigned to each pool to any value at any time.
- The owner can set the maximum stake limit to any value at any time.
Audit Results
Vulnerability Category | Notes | Result |
---|---|---|
Arbitrary Jump/Storage Write | N/A | PASS |
Centralization of Control | N/A | PASS |
Compiler Issues | N/A | PASS |
Delegate Call to Untrusted Contract | N/A | PASS |
Dependence on Predictable Variables | N/A | PASS |
Ether/Token Theft | N/A | PASS |
Flash Loans | N/A | PASS |
Front Running | N/A | PASS |
Improper Events | N/A | PASS |
Improper Authorization Scheme | N/A | PASS |
Integer Over/Underflow | N/A | PASS |
Logical Issues | N/A | PASS |
Oracle Issues | N/A | PASS |
Outdated Compiler Version | N/A | PASS |
Race Conditions | N/A | PASS |
Reentrancy | N/A | PASS |
Signature Issues | N/A | PASS |
Unbounded Loops | N/A | PASS |
Unused Code | N/A | PASS |
Overall Contract Safety | PASS |
CollarSwapERC20, CollarSwapPair, and CollarSwapFactory Contracts
($) = payable function
# = non-constant function
Int = Internal
Ext = External
Pub = Public
+ [Int] ICollarSwapFactory
- [Ext] feeTo
- [Ext] feeToSetter
- [Ext] getPair
- [Ext] allPairs
- [Ext] allPairsLength
- [Ext] createPair #
- [Ext] setFeeTo #
- [Ext] setFeeToSetter #
+ [Int] ICollarSwapPair
- [Ext] name
- [Ext] symbol
- [Ext] decimals
- [Ext] totalSupply
- [Ext] balanceOf
- [Ext] allowance
- [Ext] approve #
- [Ext] transfer #
- [Ext] transferFrom #
- [Ext] DOMAIN_SEPARATOR
- [Ext] PERMIT_TYPEHASH
- [Ext] nonces
- [Ext] permit #
- [Ext] MINIMUM_LIQUIDITY
- [Ext] factory
- [Ext] token0
- [Ext] token1
- [Ext] getReserves
- [Ext] price0CumulativeLast
- [Ext] price1CumulativeLast
- [Ext] kLast
- [Ext] mint #
- [Ext] burn #
- [Ext] swap #
- [Ext] skim #
- [Ext] sync #
- [Ext] initialize #
+ [Int] ICollarSwapERC20
- [Ext] name
- [Ext] symbol
- [Ext] decimals
- [Ext] totalSupply
- [Ext] balanceOf
- [Ext] allowance
- [Ext] approve #
- [Ext] transfer #
- [Ext] transferFrom #
- [Ext] DOMAIN_SEPARATOR
- [Ext] PERMIT_TYPEHASH
- [Ext] nonces
- [Ext] permit #
+ [Lib] SafeMath
- [Int] add
- [Int] sub
- [Int] mul
+ CollarSwapERC20 (ICollarSwapERC20)
- [Pub] #
- [Int] _mint #
- [Int] _burn #
- [Prv] _approve #
- [Prv] _transfer #
- [Ext] approve #
- [Ext] transfer #
- [Ext] transferFrom #
- [Ext] permit #
+ [Lib] Math
- [Int] min
- [Int] sqrt
+ [Lib] UQ112x112
- [Int] encode
- [Int] uqdiv
+ [Int] IERC20
- [Ext] name
- [Ext] symbol
- [Ext] decimals
- [Ext] totalSupply
- [Ext] balanceOf
- [Ext] allowance
- [Ext] approve #
- [Ext] transfer #
- [Ext] transferFrom #
+ [Int] ICollarSwapCallee
- [Ext] CollarSwapCall #
+ CollarSwapPair (ICollarSwapPair, CollarSwapERC20)
- [Pub] getReserves
- [Prv] _safeTransfer #
- [Pub] #
- [Ext] initialize #
- [Prv] _update #
- [Prv] _mintFee #
- [Ext] mint #
- modifiers: lock
- [Ext] burn #
- modifiers: lock
- [Ext] swap #
- modifiers: lock
- [Ext] skim #
- modifiers: lock
- [Ext] sync #
- modifiers: lock
+ CollarSwapFactory (ICollarSwapFactory)
- [Pub] #
- [Ext] allPairsLength
- [Ext] createPair #
- [Ext] setFeeTo #
- [Ext] setFeeToSetter #
CollarSwapRouter Contract
($) = payable function
# = non-constant function
Int = Internal
Ext = External
Pub = Public
+ [Int] ICollarSwapFactory
- [Ext] feeTo
- [Ext] feeToSetter
- [Ext] getPair
- [Ext] allPairs
- [Ext] allPairsLength
- [Ext] createPair #
- [Ext] setFeeTo #
- [Ext] setFeeToSetter #
+ [Lib] TransferHelper
- [Int] safeApprove #
- [Int] safeTransfer #
- [Int] safeTransferFrom #
- [Int] safeTransferETH #
+ [Int] ICollarSwapRouter01
- [Ext] factory
- [Ext] WETH
- [Ext] addLiquidity #
- [Ext] addLiquidityETH ($)
- [Ext] removeLiquidity #
- [Ext] removeLiquidityETH #
- [Ext] removeLiquidityWithPermit #
- [Ext] removeLiquidityETHWithPermit #
- [Ext] swapExactTokensForTokens #
- [Ext] swapTokensForExactTokens #
- [Ext] swapExactETHForTokens ($)
- [Ext] swapTokensForExactETH #
- [Ext] swapExactTokensForETH #
- [Ext] swapETHForExactTokens ($)
- [Ext] quote
- [Ext] getAmountOut
- [Ext] getAmountIn
- [Ext] getAmountsOut
- [Ext] getAmountsIn
+ [Int] ICollarSwapRouter02 (ICollarSwapRouter01)
- [Ext] removeLiquidityETHSupportingFeeOnTransferTokens #
- [Ext] removeLiquidityETHWithPermitSupportingFeeOnTransferTokens #
- [Ext] swapExactTokensForTokensSupportingFeeOnTransferTokens #
- [Ext] swapExactETHForTokensSupportingFeeOnTransferTokens ($)
- [Ext] swapExactTokensForETHSupportingFeeOnTransferTokens #
+ [Int] ICollarSwapPair
- [Ext] name
- [Ext] symbol
- [Ext] decimals
- [Ext] totalSupply
- [Ext] balanceOf
- [Ext] allowance
- [Ext] approve #
- [Ext] transfer #
- [Ext] transferFrom #
- [Ext] DOMAIN_SEPARATOR
- [Ext] PERMIT_TYPEHASH
- [Ext] nonces
- [Ext] permit #
- [Ext] MINIMUM_LIQUIDITY
- [Ext] factory
- [Ext] token0
- [Ext] token1
- [Ext] getReserves
- [Ext] price0CumulativeLast
- [Ext] price1CumulativeLast
- [Ext] kLast
- [Ext] mint #
- [Ext] burn #
- [Ext] swap #
- [Ext] skim #
- [Ext] sync #
- [Ext] initialize #
+ [Lib] SafeMath
- [Int] add
- [Int] sub
- [Int] mul
+ [Lib] CollarSwapLibrary
- [Int] sortTokens
- [Int] pairFor
- [Int] getReserves
- [Int] quote
- [Int] getAmountOut
- [Int] getAmountIn
- [Int] getAmountsOut
- [Int] getAmountsIn
+ [Int] IERC20
- [Ext] name
- [Ext] symbol
- [Ext] decimals
- [Ext] totalSupply
- [Ext] balanceOf
- [Ext] allowance
- [Ext] approve #
- [Ext] transfer #
- [Ext] transferFrom #
+ [Int] IWETH
- [Ext] deposit ($)
- [Ext] transfer #
- [Ext] withdraw #
+ CollarSwapRouter (ICollarSwapRouter02)
- [Pub] #
- [Ext] ($)
- [Int] _addLiquidity #
- [Ext] addLiquidity #
- modifiers: ensure
- [Ext] addLiquidityETH ($)
- modifiers: ensure
- [Pub] removeLiquidity #
- modifiers: ensure
- [Pub] removeLiquidityETH #
- modifiers: ensure
- [Ext] removeLiquidityWithPermit #
- [Ext] removeLiquidityETHWithPermit #
- [Pub] removeLiquidityETHSupportingFeeOnTransferTokens #
- modifiers: ensure
- [Ext] removeLiquidityETHWithPermitSupportingFeeOnTransferTokens #
- [Int] _swap #
- [Ext] swapExactTokensForTokens #
- modifiers: ensure
- [Ext] swapTokensForExactTokens #
- modifiers: ensure
- [Ext] swapExactETHForTokens ($)
- modifiers: ensure
- [Ext] swapTokensForExactETH #
- modifiers: ensure
- [Ext] swapExactTokensForETH #
- modifiers: ensure
- [Ext] swapETHForExactTokens ($)
- modifiers: ensure
- [Int] _swapSupportingFeeOnTransferTokens #
- [Ext] swapExactTokensForTokensSupportingFeeOnTransferTokens #
- modifiers: ensure
- [Ext] swapExactETHForTokensSupportingFeeOnTransferTokens ($)
- modifiers: ensure
- [Ext] swapExactTokensForETHSupportingFeeOnTransferTokens #
- modifiers: ensure
- [Pub] quote
- [Pub] getAmountOut
- [Pub] getAmountIn
- [Pub] getAmountsOut
- [Pub] getAmountsIn
CollarStake Contract
($) = payable function
# = non-constant function
Int = Internal
Ext = External
Pub = Public
+ [Int] IERC20
- [Ext] totalSupply
- [Ext] decimals
- [Ext] symbol
- [Ext] name
- [Ext] getOwner
- [Ext] balanceOf
- [Ext] transfer #
- [Ext] allowance
- [Ext] approve #
- [Ext] transferFrom #
+ Context
- [Pub] #
- [Int] _msgSender
- [Int] _msgData
+ Ownable (Context)
- [Pub] #
- [Pub] owner
- [Pub] transferOwnership #
- modifiers: onlyOwner
- [Int] _transferOwnership #
+ ReentrancyGuard
- [Pub] #
+ Pausable (Context)
- [Pub] #
- [Pub] paused
- [Int] _pause #
- modifiers: whenNotPaused
- [Int] _unpause #
- modifiers: whenPaused
+ CollarStake (Ownable, ReentrancyGuard, Pausable)
- [Pub] #
- [Ext] viewUserDetails
- [Ext] veiwPools
- [Ext] userStakeIDs
- [Ext] updateMaxTokenStake #
- modifiers: onlyOwner,whenNotPaused
- [Ext] pause #
- modifiers: onlyOwner
- [Ext] unPause #
- modifiers: onlyOwner
- [Ext] updatePoolAPYpercentage #
- modifiers: onlyOwner,whenNotPaused
- [Ext] updateCoolDownTime #
- modifiers: onlyOwner,whenNotPaused
- [Ext] updateCollarToken #
- modifiers: onlyOwner,whenNotPaused
- [Ext] poolCreation #
- modifiers: onlyOwner,whenNotPaused
- [Ext] poolStatus #
- modifiers: onlyOwner,whenNotPaused
- [Ext] stake #
- modifiers: nonReentrant,whenNotPaused
- [Ext] unstake #
- modifiers: nonReentrant,whenNotPaused
- [Ext] withdraw #
- [Pub] claimReward #
- [Pub] pendingReward
- [Ext] adminDeposit #
- modifiers: onlyOwner
CollarFlexStake Contract
($) = payable function
# = non-constant function
Int = Internal
Ext = External
Pub = Public
+ [Int] IERC20
- [Ext] totalSupply
- [Ext] decimals
- [Ext] symbol
- [Ext] name
- [Ext] getOwner
- [Ext] balanceOf
- [Ext] transfer #
- [Ext] allowance
- [Ext] approve #
- [Ext] transferFrom #
+ Context
- [Pub] #
- [Int] _msgSender
- [Int] _msgData
+ Ownable (Context)
- [Pub] #
- [Pub] owner
- [Pub] transferOwnership #
- modifiers: onlyOwner
- [Int] _transferOwnership #
+ ReentrancyGuard
- [Pub] #
+ Pausable (Context)
- [Pub] #
- [Pub] paused
- [Int] _pause #
- modifiers: whenNotPaused
- [Int] _unpause #
- modifiers: whenPaused
+ CollarFlexStake (Ownable, ReentrancyGuard, Pausable)
- [Pub] #
- [Ext] viewUserDetails
- [Ext] veiwPools
- [Ext] userStakeIDs
- [Ext] updateMaxTokenStake #
- modifiers: onlyOwner
- [Ext] pause #
- modifiers: onlyOwner
- [Ext] unPause #
- modifiers: onlyOwner
- [Ext] updatePoolAPYpercentage #
- modifiers: onlyOwner
- [Ext] updateCollarToken #
- modifiers: onlyOwner
- [Ext] poolCreation #
- modifiers: onlyOwner
- [Ext] poolStatus #
- modifiers: onlyOwner
- [Ext] stake #
- modifiers: nonReentrant,whenNotPaused
- [Ext] withdraw #
- modifiers: nonReentrant,whenNotPaused
- [Pub] claimReward #
- modifiers: whenNotPaused
- [Pub] pendingReward
- [Ext] adminDeposit #
- modifiers: onlyOwner
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Typically, a smart contract audit is a comprehensive review process designed to discover logical errors, security vulnerabilities, and optimization opportunities within code. A SourceHat Audit takes this a step further by verifying economic logic to ensure the stability of smart contracts and highlighting privileged functionality to create a report that is easy to understand for developers and community members alike.
How Do I Interpret the Findings?
Each of our Findings will be labeled with a Severity level. We always recommend the team resolve High, Medium, and Low severity findings prior to deploying the code to the mainnet. Here is a breakdown on what each Severity level means for the project:
- High severity indicates that the issue puts a large number of users' funds at risk and has a high probability of exploitation, or the smart contract contains serious logical issues which can prevent the code from operating as intended.
- Medium severity issues are those which place at least some users' funds at risk and has a medium to high probability of exploitation.
- Low severity issues have a relatively minor risk association; these issues have a low probability of occurring or may have a minimal impact.
- Informational issues pose no immediate risk, but inform the project team of opportunities for gas optimizations and following smart contract security best practices.