Submitted by kirk-baird
There is a Centralisation risk of the bridge where the DEFAULT_ADMIN_ROLE of TokenManagerEth.sol is able to modify the ERC20 token on the SChain to any arbitrary address. This would allow the admin role to change the address to one where they have infinite supply, they could then call exitToMain(amount) equal to the balance of the DepositBox in the main Ethereum chain. After the message is process on the main Ethereum chain they will receive the entire Eth balance of that contract.
The rug pull attack occurs because there is a DEFAULT_ADMIN_ROLE which is set in the intiialisation to the msg.sender as seen in initializeTokenManager() below.
The DEFAULT_ADMIN_ROLE may then call setEthErc20Address(IEthErc20 newEthErc20Address)  setting newEthErc20Address to any arbitrary contract they control.
Consider removing the function setEthErc20Address() as ethErc20 is set in the initialize() function and does not need to be changed.
DimaStebaev (SKALE) disagreed with severity and commented:
GalloDaSballo (judge) commented:
