Submitted by Reigada, also found by WatchPug
As we can see in the contracts AirdropDistribution and InvestorDistribution, they both have the following approve() call: mainToken.approve(address(vestLock), 2\*\*256-1);
This is necessary because both contracts transfer tokens to the vesting contract by calling its vest() function:
The code of the vest() function in the Vesting contract performs a transfer from msg.sender to Vesting contract address -> vestingToken.transferFrom(msg.sender, address(this), \_amount);
https://github.com/code-423n4/2021-11-bootfinance/blob/main/vesting/contracts/Vesting.sol#L95
Same is done in the BasicSale contract:
https://github.com/code-423n4/2021-11-bootfinance/blob/main/tge/contracts/PublicSale.sol#L225
The problem is that this contract is missing the approve() call. For that reason, the contract is totally useless as the function \_withdrawShare() will always revert with the following message:
revert reason: ERC20: transfer amount exceeds allowance. This means that all the mainToken sent to the contract would be stuck there forever. No way to retrieve them.
How this issue was not detected in the testing phase?
Very simple. The mock used by the team has an empty vest() function that performs no transfer call.
https://github.com/code-423n4/2021-11-bootfinance/blob/main/tge/contracts/helper/MockVesting.sol#L10
See below Brownies custom output:
Manual testing
The following approve() call should be added in the constructor of the BasicSale contract:
mainToken.approve(address(vestLock), 2\*\*256-1);
chickenpie347 (Boot Finance) confirmed 
