{"id":"CVE-2021-41138","aliases":["GHSA-vj62-g63v-f8mf"],"title":"Validity check missing in Frontier","summary":"Validity check missing in Frontier","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","vendor":"pallet-ethereum","product":"pallet-ethereum","ecosystem":"rust","affected":["pallet-ethereum <= 3.0.0"],"published":"2021-10-13","updated":"2026-07-08","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-vj62-g63v-f8mf","references":[{"url":"https://github.com/paritytech/frontier/security/advisories/GHSA-vj62-g63v-f8mf"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-41138"},{"url":"https://github.com/paritytech/frontier/pull/495"},{"url":"https://github.com/paritytech/frontier/pull/497"},{"url":"https://github.com/paritytech/frontier/commit/146bb48849e5393004be5c88beefe76fdf009aba"},{"url":"https://github.com/polkadot-evm/frontier"}],"tags":["osv","rust"],"epss":0.01383,"epssPercentile":0.71,"ingestedAt":"2026-07-09T18:56:37.332Z","slug":"CVE-2021-41138","body":"## Overview\n\n### Impact\n\nIn the newly introduced signed Frontier-specific extrinsic for `pallet-ethereum`, a large part of transaction validation logic was only called in transaction pool validation, but not in block execution. Malicious validators can take advantage of this to put invalid transactions into a block.\n\nThe attack is limited in that the signature is always validated, and the majority of the validation is done again in the subsequent `pallet-evm` execution logic. However, do note that a chain ID replay attack was possible. In addition, spamming attacks are of main concerns, while they are limited by Substrate block size limits and other factors.\n\n### Patches\n\nThe issue is patched in commit 146bb48849e5393004be5c88beefe76fdf009aba.\n\n### References\n\nPatch PR: https://github.com/paritytech/frontier/pull/495\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n* Open an issue in [Frontier repo](https://github.com/paritytech/frontier/issues)\n\n### Special thanks\n\nSpecial thanks to @librelois, @nanocryk and the Moonbeam team for reporting and fixing this security vulnerability.\n\n## Affected packages\n\n- `pallet-ethereum <= 3.0.0`\n\n## Remediation\n\nRefer to the advisory for the patched release.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0.3,"exploitation":0,"ransomware":0},"changes":[]}