{"cve":"CVE-2021-41138","nvd":{"published":"2021-10-13T16:15:07.847","modified":"2026-06-17T04:07:57.040","status":"Modified","description":"Frontier is Substrate's Ethereum compatibility layer. In 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. The 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. The issue is patched in commit `146bb48849e5393004be5c88beefe76fdf009aba`.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":5.3},"cwes":["CWE-20"],"references":["https://github.com/paritytech/frontier/commit/146bb48849e5393004be5c88beefe76fdf009aba","https://github.com/paritytech/frontier/pull/497","https://github.com/paritytech/frontier/security/advisories/GHSA-vj62-g63v-f8mf","https://github.com/paritytech/frontier/commit/146bb48849e5393004be5c88beefe76fdf009aba","https://github.com/paritytech/frontier/pull/497"],"products":["parity:frontier"],"source":"nvd","synced_at":"2026-10-19T21:24:39.218183596+00:00"},"epss":{"cve":"CVE-2021-41138","score":0.01383,"percentile":0.72183,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-vj62-g63v-f8mf","url":"https://osv.dev/vulnerability/GHSA-vj62-g63v-f8mf","summary":"Validity check missing in Frontier","modified":"2026-07-08T06:28:30.103519272Z","packages":[{"ecosystem":"crates.io","name":"pallet-ethereum","purl":"pkg:cargo/pallet-ethereum","ranges":["<=3.0.0"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}