{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "1.8.19"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "dae82f098570e15d44584f0d7f350713f4774727"
            }
          ],
          "repo": "https://github.com/ethereum/go-ethereum",
          "type": "GIT"
        }
      ]
    }
  ],
  "details": "Go Ethereum (aka geth) 1.8.19 allows attackers to cause a denial of service (memory consumption) by rewriting the length of a dynamic array in memory, and then writing data to a single memory location with a large index number, as demonstrated by use of \"assembly { mstore }\" followed by a \"c[0xC800000] = 0xFF\" assignment.",
  "id": "CVE-2018-20421",
  "modified": "2026-03-13T21:50:57.388412533Z",
  "published": "2018-12-24T03:29:00.353Z",
  "references": [
    {
      "type": "EVIDENCE",
      "url": "https://github.com/ethereum/go-ethereum/issues/18289"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}