Submitted by berndartmueller, also found by dontonka
Cross-chain Zeta messages originating from the zEVM have the user-specified destination gas limit ignored (hardcoded to 90000), potentially causing the transaction to fail with an out-of-gas error.
As a result, the cctx is aborted without refunding the sender, thus causing the sender to lose funds.
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 the destinationGasLimit to ensure sufficient gas is used, in case the cross-chain message, once received by the onReceive function of the ZetaConnector contract on the receiver chain (e.g., ZetaConnectorEth or ZetaConnectorNonEth) calls the destinationAddresss onZetaMessage function.
However, this user-specified gas limit (destinationGasLimit) is not used, instead, it is hardcoded in line 224 to 90000.
Please note that the observers EVM signer lower-bounds the gas limit to 100k.
As the transactions gas limit is set to 90k, and subsequently overwritten to the lower bound of 100k, the transaction potentially fails with an out-of-gas error, preventing the transaction from being processed.
The sender of the cross-chain Zeta message may have anticipated this and thus specified a higher destinationGasLimit in the first place to ensure the transaction succeeds, which is unfortunately ignored.
Consider using the user-specified destinationGasLimit instead of hardcoding the gas limit to 90000.
lumtis (ZetaChain) acknowledged
