BitDCA

### BDCAVesting In the contract `BDCAVesting`, the role `_owner` has authority over the functions shown in the diagram below. Any compromise to the `_owner` account may allow the hacker to take advantage of this authority and transfer or renounce ownership, and set vesting schedules and allocations for multiple addresses once.  ### BDCAVestingCEX In the contract `BDCAVestingCEX`, the role `_manager` has authority over the functions shown in the diagram below. Any compromise to the `_manager` account may allow the hacker to take advantage of this authority and start the vesting process allowing the user to claim tokens.  ---- In the contract `BDCAVestingCEX`, the role `_owner` has authority over the functions shown in the diagram below. Any compromise to the `_owner` account may allow the hacker to take advantage of this authority and transfer or renounce ownership, set the manager address as long as the contract is not activated, and set vesting allocations for multiple addresses once as long as the contract is not activated. 

All of the `BDCA Token` tokens are sent to the contract deployer. This is a centralization risk because the deployer can distribute tokens without obtaining the consensus of the community. Any compromise to these addresses may allow a hacker to steal and sell tokens on the market, resulting in severe damage to the project.

The codebase contains multiple Solidity versions, which can lead to unexpected behavior, potential vulnerabilities, difficulties in maintaining the code, and inconsistencies in the execution of the smart contract. Using different versions may also result in increased complexity during code auditing, as different security features and bug fixes are present in different versions of the compiler. Versions used: `^0.8.20`, `^0.8.9` ```solidity=3 pragma solidity ^0.8.20; ``` `^0.8.20` is used in contracts/BDCAVestingCEX.sol file. ```solidity=3 pragma solidity ^0.8.20; ``` ```solidity=2 pragma solidity ^0.8.9; ``` `^0.8.9` is used in contracts/BDCA.sol file. ```solidity=2 pragma solidity ^0.8.9; ```