{"id":"CVE-2018-20421","aliases":["EUVD-2018-12978","GHSA-5g4w-3m99-4m2p"],"status":"published","title":"Go Ethereum (aka geth) 1.8.19 allows attackers to cause a denial of service (memory consumption)...","description":"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.","severity":{"version":"3.0","score":7.5,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.01456,"percentile":0.7367,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-770"],"published":"2018-12-24T03:00:00Z","modified":"2026-10-20T10:50:06Z","products":[{"vendor":"ethereum","product":"go_ethereum"}],"references":[{"url":"https://github.com/ethereum/go-ethereum/issues/18289","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","evidence"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2018-20421"},{"url":"https://github.com/advisories/GHSA-5g4w-3m99-4m2p"}],"sources":{"cve":[{"id":"CVE-2018-20421","description":"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.","status":"published","published":"2018-12-24T03:00:00Z","modified":"2024-09-17T01:41:26.479Z","updated_at":"2026-11-02T14:34:59.872731Z"}],"euvd":[{"id":"EUVD-2018-12978","description":"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.","status":"published","published":"2018-12-24T03:00:00Z","modified":"2024-09-17T01:41:26Z","updated_at":"2026-11-03T00:28:47.497259Z"}],"ghsa":[{"id":"GHSA-5g4w-3m99-4m2p","title":"Go Ethereum (aka geth) 1.8.19 allows attackers to cause a denial of service (memory consumption)...","description":"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.","status":"published","published":"2022-05-13T01:51:03Z","modified":"2023-02-02T05:02:05Z","cvss":[{"version":"3.0","score":7.5,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:51:20.767191Z"}],"nvd":[{"id":"CVE-2018-20421","description":"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.","status":"published","published":"2018-12-24T03:29:00.353Z","modified":"2026-06-17T01:52:48.627Z","cvss":[{"version":"3.0","score":7.5,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:04:50.99633Z"}],"osv":[{"id":"CVE-2018-20421","description":"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.","status":"published","published":"2018-12-24T03:29:00.353Z","modified":"2026-10-20T10:50:06.35466578Z","cvss":[{"version":"3.0","score":7.5,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:09.145458Z"}]}}