Yieldy contest - oyc_109's results

Lines of code

https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L471

Vulnerability details

inconsistent safeTransfer usage

description

It is good to add a require() statement that checks the return value of token transfers or to use something like OpenZeppelin’s safeTransfer/safeTransferFrom unless one is sure the given token reverts in case of a failure. Failure to do so will cause silent failures of transfers and affect token accounting in contract.

https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L471

missing checks for zero address

description

Checking addresses against zero-address during initialization or during setting is a security best-practice. However, such checks are missing in address variable initializations/changes in many places.

Impact: Allowing zero-addresses will lead to contract reverts and force redeployments if there are no setters for such address variables.

findings

https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L71-L72 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L158 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L178

Use of Block.timestamp

description

Block timestamps have historically been used for a variety of applications, such as entropy for random numbers (see the Entropy Illusion for further details), locking funds for periods of time, and various state-changing conditional statements that are time-dependent. Miners have the ability to adjust timestamps slightly, which can prove to be dangerous if block timestamps are used incorrectly in smart contracts.

recommendation

Block timestamps should not be used for entropy or generating random numbers—i.e., they should not be the deciding factor (either directly or through some derivation) for winning a game or changing an important state.

Time-sensitive logic is sometimes required; e.g., for unlocking contracts (time-locking), completing an ICO after a few weeks, or enforcing expiry dates. It is sometimes recommended to use block.number and an average block time to estimate times; with a 10 second block time, 1 week equates to approximately, 60480 blocks. Thus, specifying a block number at which to change a contract state can be more secure, as miners are unable to easily manipulate the block number.

findings

https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L97 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L361 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L707 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Yieldy.sol#L86 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Yieldy.sol#L129

admin can drain funds

description

The current design/implementation allows a adminto call transferToke() and transfer tokens to an arbitrary address.

recommendation: Consider adding constrains (eg. timelock)

https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L141-L151

use of x = x + y is cheaper than x += y

https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L310 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L309 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L494 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L694

don't use && require statement

description

The code size on deployment can be a bit smaller to save gas

findings

https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L605-L609 https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L611-L614

Long Revert Strings

description

Shortening revert strings to fit in 32 bytes will decrease gas costs for deployment and gas costs when the revert condition has been met.

If the contract(s) in scope allow using Solidity >=0.8.4, consider using Custom Errors as they are more gas efficient while allowing developers to describe the error in detail using NatSpec.

using prefix increments save gas

description

Prefix increments are cheaper than postfix increments, eg ++i rather than i++

findings

https://github.com/code-423n4/2022-06-yieldy/blob/524f3b83522125fb7d4677fa7a7e5ba5a2c0fe67/src/contracts/Staking.sol#L708