[M] Unused gasValue is not refunded when calling deployRemoteCanonicalToken to the destination chain

[code423n4]

Lines of code

https://github.com/code-423n4/2023-07-axelar/blob/2f9b234bb8222d5fbe934beafede56bfb4522641/contracts/its/interchain-token-service/InterchainTokenService.sol#L325

Vulnerability details

Impact

In InterchainTokenService, its used to deploy multiple tokenManagers on different chains.

According to the dev comments:

• @dev gasValue exists because this function can be part of a multicall involving
  multiple functions that could make remote contract calls.

However, when deployRemoteCanonicalToken is called, the gasValue sent could exceed the required gas fee for the function to execute successfully on the destination chain.

Proof of Concept

Occasionally, transactions can get "stuck" in the pipeline from a source to destination chain
(e.g. due to one-off issues that arise with relayers that operate on top of the network).

Transactions have typically gotten "stuck" in the pipeline due to:

1. The transaction failing to relay from the source chain into the Axelar network for processing.
2. The transaction failing to get executed on the destination chain.

This will lead to in some instances excess gas being sent and not used.
Therefore, the excess gas will not be refunded to the user.

This is existential across a few functions in InterchainTokenService.

Including deployAndRegisterRemoteStandardizedToken and deployRemoteCustomTokenManager.

Tools Used

Manual Review

Recommended Mitigation Steps

I would suggest to use a gas refund mechanism to refund the unused gas to the user or
provide a cancel option if the transaction failed, from the source chain or destination chain,
and allow the user to get the gas refund.

Assessed type

Other

[c4-pre-sort]

0xSorryNotSorry marked the issue as duplicate of #316

[c4-judge]

berndartmueller marked the issue as not a duplicate

[berndartmueller]

Wrongly duplicated to #316

Kindly invite the sponsor's feedback. @deanamiel

[c4-sponsor]

deanamiel (sponsor) disputed

[deanamiel]

This is not a code related issue specific to the interchain token service, it is a more general concern related to the Axelar stack as a whole. There should not be any calls that get stuck like this.

[berndartmueller]

Invalidating the submission. Failed transactions during relaying should be paid from the provided gas fees by the user to compensate the relayer.

[c4-judge]

berndartmueller marked the issue as unsatisfactory:
Invalid