{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.0.1"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "cb6d807a697d952916a0c46ce05ddd4d78718ca7"
            },
            {
              "fixed": "d136170666e9510eb63c2572551805807bd4c17f"
            }
          ],
          "repo": "https://github.com/starkbank/ecdsa-python",
          "type": "GIT"
        }
      ]
    }
  ],
  "details": "The verify function in the Stark Bank Python ECDSA library (aka starkbank-escada or ecdsa-python) before 2.0.1 fails to check that the signature is non-zero, which allows attackers to forge signatures on arbitrary messages.",
  "id": "CVE-2021-43572",
  "modified": "2026-03-13T21:55:00.416511390Z",
  "published": "2021-11-09T22:15:07.727Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/starkbank/ecdsa-python/releases/tag/v2.0.1"
    },
    {
      "type": "FIX",
      "url": "https://github.com/starkbank/ecdsa-python/commit/d136170666e9510eb63c2572551805807bd4c17f"
    },
    {
      "type": "EVIDENCE",
      "url": "https://research.nccgroup.com/2021/11/08/technical-advisory-arbitrary-signature-forgery-in-stark-bank-ecdsa-libraries/"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}