Xshares

In the contract `XSharesSharesV1` 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 modify important configurations of the contract, such as the fee amount and fee destination. 

The “XSharesSharesV2” contract inherits upgradeable contracts, indicating that it’s part of an upgradeable system. Upgradeable contracts often pair with a proxy contract responsible for managing contract upgrades. The `admin` of the proxy has the authority to update the implementation contract (i.e., the XSharesSharesV2 contract). Any compromise of the admin account could allow a hacker to exploit this authority, potentially altering the implementation contract pointed to by the proxy, and thus executing malicious functionality within the implementation contract.

There are no upper boundaries for **setProtocolFeePercent** and **setSubjectFeePercent** function which is used to modify the protocol fee and subject fee. It is possible to set the total fee rate up to any arbitrary amount.

The contract requires the "sharesSubject" to have at least 1 share after the registration. The last share of the "sharesSubject" will become unsellable. It's possible for a regular user's share to become unsellable, and the user will lose its assets. ```sol require(supply > amount, "Cannot sell the last share"); ```

The smart contract contains one or more state changes related to arithmetic operations that do not emit events to communicate the changes outside the blockchain, which can lead to difficulties in tracking or verifying these changes and may affect the contract's transparency and auditability. ```solidity=147 protocolFeePercent = _feePercent; ``` --- ```solidity=151 subjectFeePercent = _feePercent; ```

The "register" function allows an EOA or smart contract to register a "sharesSubject." When selling or buying shares, the "sharesSubject" address needs to receive native tokens. If the "sharesSubject" is malicious or has incorrectly implemented the payment receive feature, it can cause the "XSharesSharesV2" to malfunction. The implementation of all the "sharesSubject" instances is out of the scope of the audit.

One or more logic contracts do not protect their initializers. An attacker can call the initializer and assume ownership of the logic contract, whereby she can perform privileged operations that trick unsuspecting users into believing that she is the owner of the upgradeable contract. ```solidity=6 contract XSharesSharesV2 is OwnableUpgradeable { ``` - `XSharesSharesV2` is an upgradeable contract that does not protect its initializer. ```solidity=23 function initialize() public initializer { ``` - `initialize` is an unprotected initializer function.