{"id":"CVE-2022-21685","aliases":["GHSA-cjg2-2fjg-fph4"],"url":"https://o3.security/vulnerability/CVE-2022-21685","summary":"Integer underflow in Frontier","details":"Frontier is Substrate's Ethereum compatibility layer. Prior to commit number `8a93fdc6c9f4eb1d2f2a11b7ff1d12d70bf5a664`, a bug in Frontier's MODEXP precompile implementation can cause an integer underflow in certain conditions. This will cause a node crash for debug builds. For release builds (and production WebAssembly binaries), the impact is limited as it can only cause a normal EVM out-of-gas. Users who do not use MODEXP precompile in their runtime are not impacted. A patch is available in pull request #549.","published":"2022-01-14T17:05:11Z","modified":"2026-08-12T03:51:10.631938613Z","cvss":{"score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.01331,"percentile":0.68481,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"pallet-evm-precompile-modexp","fixedVersion":null}],"fix":{"url":"https://github.com/paritytech/frontier/commit/8a93fdc6c9f4eb1d2f2a11b7ff1d12d70bf5a664","label":"paritytech/frontier@8a93fdc"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/21xxx/CVE-2022-21685.json"},{"type":"ADVISORY","url":"https://github.com/paritytech/frontier/security/advisories/GHSA-cjg2-2fjg-fph4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-21685"},{"type":"FIX","url":"https://github.com/paritytech/frontier/commit/8a93fdc6c9f4eb1d2f2a11b7ff1d12d70bf5a664"},{"type":"FIX","url":"https://github.com/paritytech/frontier/pull/549"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:10.631938613Z"}}