{"id":"CVE-2021-41138","aliases":["GHSA-vj62-g63v-f8mf"],"url":"https://o3.security/vulnerability/CVE-2021-41138","summary":"Validity check missing in Frontier","details":"### 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.","published":"2021-10-13T16:15:07.847Z","modified":"2026-07-08T06:28:36.543190698Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"pallet-ethereum","fixedVersion":null}],"fix":{"url":"https://github.com/paritytech/frontier/commit/146bb48849e5393004be5c88beefe76fdf009aba","label":"paritytech/frontier@146bb48"},"references":[{"type":"FIX","url":"https://github.com/paritytech/frontier/commit/146bb48849e5393004be5c88beefe76fdf009aba"},{"type":"FIX","url":"https://github.com/paritytech/frontier/pull/497"},{"type":"FIX","url":"https://github.com/paritytech/frontier/security/advisories/GHSA-vj62-g63v-f8mf"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-41138"},{"type":"WEB","url":"https://github.com/paritytech/frontier/pull/495"},{"type":"PACKAGE","url":"https://github.com/polkadot-evm/frontier"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-08T06:28:36.543190698Z"}}