Submitted by berndartmueller, also found by MevSec
Cross-chain Zeta messages originating from the zEVM have an empty message field, preventing the destinationAddress contract from being called.
This renders the cross-chain messaging functionality useless as the message is never used and potentially causes a loss of funds (if assets have been burned on the zEVM) or locked funds (if unable to unlock on the receiver end).
zEVM transactions are post-processed in the PostTxProcessing function of the x/crosschain module. Specifically, the goal is to parse and process ZetaSent and ZRC-20 Withdrawal events and send them to the corresponding, external receiver chains.
Any emitted ZetaSent events are parsed and processed in the ProcessZetaSentEvent function. This event is emitted by the ZetaConnectorZEVM.send function to send a cross-chain message to an external chain.
The message input, ZetaInterfaces.SendInput, allows the sender to specify a message that is forwarded to the receiver contract (destinationAddress) on the destination chain.
Specifically, once the cross-chain message is received by the onReceive function of the ZetaConnector contract on the receiver chain (e.g., ZetaConnectorEth or ZetaConnectorNonEth), the destinationAddresss onZetaMessage function is called and the message is provided as a parameter.
However, the user-specified message is not used, instead, it is overwritten by an empty string in line 221.
As a result, the destination contract is never called as the message is empty.
Consider using the user-specified message instead of overwriting it with an empty string.
lumtis (ZetaChain) confirmed
