{"id":"CVE-2021-43568","aliases":["GHSA-xx36-6rv4-gj8r"],"url":"https://o3.security/vulnerability/CVE-2021-43568","summary":"ecdsa-elixir fails to check signatures, vulnerable to message forging","details":"The verify function in the Stark Bank Elixir ECDSA library (ecdsa-elixir) 1.0.0 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.","published":"2021-11-09T22:15:07.553Z","modified":"2026-07-09T05:45:33.283030Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"Hex","name":"ecdsa-elixir","fixedVersion":"1.0.1"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/starkbank/ecdsa-elixir/releases/tag/v1.0.1"},{"type":"EVIDENCE","url":"https://research.nccgroup.com/2021/11/08/technical-advisory-arbitrary-signature-forgery-in-stark-bank-ecdsa-libraries/"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T05:45:33.283030Z"}}