CVE intelligence and bounded remediation

CVE-2021-25835 — Cosmos Network Ethermint <= v0.4.0 is affected by a cross-chain transaction replay vulnerability in the EVM module

High CVSS 7.5

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.

Severity
High
CVSS
7.5 (3.1)
Published
2021-02-08
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-294

Affected products

  • chainsafe / ethermint

Matched remediation archetype

Authentication bypass and missing authentication

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Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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