GoGoPool contest - SEVEN's results

Lines of code

https://github.com/code-423n4/2022-12-gogopool/blob/main/contracts/contract/tokens/upgradeable/ERC4626Upgradeable.sol#L42-L54 https://github.com/code-423n4/2022-12-gogopool/blob/main/contracts/contract/tokens/upgradeable/ERC4626Upgradeable.sol#L132-L133 https://github.com/code-423n4/2022-12-gogopool/blob/main/contracts/contract/tokens/upgradeable/ERC4626Upgradeable.sol#L120-L124

Vulnerability details

Impact

A malicious early user can deposit() with 1 wei of asset token as the first depositor of the LToken, and get 1 wei of shares.

Then the attacker can send 10000e18 - 1 of asset tokens and inflate the price per share from 1.0000 to an extreme value of 1.0000e22 ( from (1 + 10000e18 - 1) / 1) .

As a result, the future user who deposits 19999e18 will only receive 1 wei (from 19999e18 * 1 / 10000e18) of shares token.

They will immediately lose 9999e18 or half of their deposits if they redeem() right after the deposit().

Proof of Concept

Provide direct links to all referenced code in GitHub. Add screenshots, logs, or any other relevant proof that illustrates the concept.

Tools Used

vscode Consider requiring a minimal amount of share tokens to be minted for the first minter, and send a port of the initial mints as a reserve to the DAO so that the pricePerShare can be more resistant to manipulation.