Describe CVE-2021-25835.
What is CVE-2021-25835?
Cosmos Network Ethermint <= v0.4.0 is affected by a cross-chain transaction replay vulnerability in the EVM module. Since ethermint uses the same chainIDEpoch and signature schemes with ethereum for compatibility, a verified signature in ethereum is still valid in ethermint with the same msg content and chainIDEpoch, which enables "cross-chain transaction replay" attack..