Schain owners can rug pull users' funds

Lines of code Vulnerability details Impact Once a chain has been killed the chain owner is able to call getFunds on each of the deposit boxes and transfer funds/tokens wherever he/she wishes Even if the owner is benevolent the fact that there is a rug vector available may negatively impact the...

Possible underflow when exit to mainnet with full amount after receiving tokens from another schain

Lines of code Vulnerability details Impact When tokens are transferred from one schain to another schain, the outgoing messages are not transmitted to the mainnet receiver. The amount of tokens on the receiving schain will increase but when exiting on mainnet with the full amount, it will cause...

Schain owner dictate fund usage after kill

Lines of code Vulnerability details Impact After a schain is killed by both the owner and the IMA admin, schain admin can control all the fund using e.g. DepositBoxERC20.getFunds functions. This pose a significant centralization risk after the schain is killed. Proof of Concept function...

Deposit Box Does Not Account for Fee On Transfer Tokens Causing the Bridge To Absorb the Fees

Lines of code Vulnerability details Impact The function DepositBoxERC20.depositERC20 does not account for FoT Fee on Transfer tokens. FoT tokens charge a fee when transfer or transferFrom is called and it is subtracted from amount so the receiving address will receive less than amount of tokens...

If SChain is Removed Before kill() and getFunds() all Tokens are Locked in the Bridge

Lines of code Vulnerability details Impact If the SChain is removed before all the funds are withdrawn from the bridge they will be permanently locked in the bridge. When a SChain is removed in by the SKALE protocol via the function SchainsInternal.removeSchain the data including the owner will b...

Gas Pricing Can Be Used To Extort Funds From Users of SChain Owner

Lines of code Vulnerability details Impact The function refundGasByUser can be exploited by the message sender to drain nodes and SChain owners of their balances when processing incoming messages. When a node collates a set of exits from an SChain to Ethereum, they are submitted on-chain via...