{"id":"CVE-2021-43571","aliases":["EUVD-2021-2379","GHSA-q9q6-f556-gpm7"],"status":"published","title":"Improper Verification of Cryptographic Signature in starkbank-ecdsa","description":"The verify function in the Stark Bank Node.js ECDSA library (ecdsa-node) 1.1.2 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.01027,"percentile":0.63857,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-347"],"published":"2021-11-09T21:05:34Z","modified":"2026-10-20T10:54:08Z","fixes":[{"ecosystem":"npm","package":"starkbank-ecdsa","fixed_in":["1.1.3"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"starkbank-ecdsa","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.1.3"}]}]},{"source":"osv","ecosystem":"npm","package":"starkbank-ecdsa","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.1.3"}]}]}],"products":[{"vendor":"starkbank","product":"ecdsa-node"}],"references":[{"url":"https://research.nccgroup.com/2021/11/08/technical-advisory-arbitrary-signature-forgery-in-stark-bank-ecdsa-libraries/","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","evidence"]},{"url":"https://github.com/starkbank/ecdsa-node/releases/tag/v1.1.3","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-43571","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-q9q6-f556-gpm7"},{"url":"https://github.com/starkbank/ecdsa-node","tags":["package"]},{"url":"https://research.nccgroup.com/2021/11/08/technical-advisory-arbitrary-signature-forgery-in-stark-bank-ecdsa-libraries","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2021-43571","description":"The verify function in the Stark Bank Node.js ECDSA library (ecdsa-node) 1.1.2 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.","status":"published","published":"2021-11-09T21:05:34Z","modified":"2024-08-04T04:03:08.651Z","updated_at":"2026-11-02T14:32:57.033395Z"}],"euvd":[{"id":"EUVD-2021-2379","description":"The verify function in the Stark Bank Node.js ECDSA library (ecdsa-node) 1.1.2 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.","status":"published","published":"2021-11-09T21:05:34Z","modified":"2024-08-04T04:03:08Z","updated_at":"2026-11-03T03:24:13.772922Z"}],"ghsa":[{"id":"GHSA-q9q6-f556-gpm7","title":"Improper Verification of Cryptographic Signature in starkbank-ecdsa","description":"The verify function in the Stark Bank Node.js ECDSA library (ecdsa-node) 1.1.2 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.","status":"published","published":"2021-11-10T20:58:42Z","modified":"2023-02-01T05:06:16Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:36:38.281533Z"}],"nvd":[{"id":"CVE-2021-43571","description":"The verify function in the Stark Bank Node.js ECDSA library (ecdsa-node) 1.1.2 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.","status":"published","published":"2021-11-09T22:15:07.683Z","modified":"2026-06-17T04:11:09.373Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T14:07:00.984108Z"}],"osv":[{"id":"CVE-2021-43571","description":"The verify function in the Stark Bank Node.js ECDSA library (ecdsa-node) 1.1.2 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.","status":"published","published":"2021-11-09T22:15:07.683Z","modified":"2026-10-20T10:54:08.827143143Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:44:21.877444Z"},{"id":"GHSA-q9q6-f556-gpm7","title":"Improper Verification of Cryptographic Signature in starkbank-ecdsa","description":"The verify function in the Stark Bank Node.js ECDSA library (ecdsa-node) 1.1.2 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.","status":"published","published":"2021-11-10T20:58:42Z","modified":"2023-11-08T04:07:10.766953Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-347"],"updated_at":"2026-11-02T15:46:54.40888Z"}]}}