Cosmos · Cosmos Network Ethermint · CVE-2021-25834
**Name of the Vulnerable Software and Affected Versions**
Cosmos Network Ethermint versions <= v0.4.0
**Description**
The issue is related to a transaction replay vulnerability in the EVM module. If a victim sends a very large nonce transaction, an attacker can replay the transaction through the application. This vulnerability affects specific Go packages, including github.com/cosmos/ethermint/rpc/namespaces/eth. The vulnerability can also be described as an authentication bypass by capture-replay.
**Recommendations**
For Cosmos Network Ethermint versions <= v0.4.0, consider disabling the EVM module or restricting its use to minimize the risk of exploitation until a patch is available. Restrict access to the github.com/cosmos/ethermint/rpc/namespaces/eth package to prevent potential abuse. Avoid using very large nonce transactions in the affected application to reduce the risk of transaction replay attacks. At the moment, there is no information about a newer version that contains a fix for this vulnerability.