Impact

In evm crate < 0.31.0, JUMPI opcode's condition is checked after the destination validity check. However, according to Geth and OpenEthereum, the condition check should happen before the destination validity check.

Patches

This is a high severity security advisory if you use evm crate for Ethereum mainnet. In this case, you should update your library dependency immediately to on or after 0.31.0.

This is a low severity security advisory if you use evm crate in Frontier or in a standalone blockchain, because there's no security exploit possible with this advisory. It is not recommended to update to on or after 0.31.0 until all the normal chain upgrade preparations have been done. If you use Frontier or other pallet-evm based Substrate blockchain, please ensure to update your spec_version before updating this. For other blockchains, please make sure to follow a hard-fork process before you update this.

Workarounds

If you are dependent on an older version of evm and cannot update due to API interface changes, please contact Wei by email (wei@that.world), who will be happy to help you to publish patch releases for older evm versions.

References

Fix PR: #67

For more information

If you have any questions or comments about this advisory:

• Open an issue in the evm repo.

Special thanks

Special thanks to @rakita for reporting this issue.