Security advisory

{
  "id": "540b1781b68110864053b90bef82486a9ec1bffa1a3544b15210a5f70273af2b",
  "url": "https://osv.dev/vulnerability/CVE-2018-20187",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2018-20187",
    "summary": "A side-channel issue was discovered in Botan before 2.9.0. An attacker capable of precisely measuring the time taken for ECC key generation may be able to derive information about the high bits of the secret key, as the function to derive the public point from the secret scalar uses an unblinded Montgomery ladder whose loop iteration count depends on the bitlength of the secret. This issue affects only key generation, not ECDSA signatures or ECDH key agreement.",
    "evidence": "osv:CVE-2018-20187",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2018-20187",
      "aliases": [
        "CVE-2018-20187"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/randombit/botan",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "a95c67a5a1fd8c9afd9cb69770cb1542f558f163"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:botan_project:botan:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.9.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.8.0",
            "2.7.0",
            "2.6.0",
            "2.5.0",
            "2.4.0",
            "2.3.0",
            "2.2.0",
            "2.1.0",
            "2.0.1",
            "2.0.0",
            "1.11.34",
            "1.11.33",
            "1.11.32",
            "1.11.31",
            "1.11.30",
            "1.11.29",
            "1.11.28",
            "1.11.27",
            "1.11.26",
            "1.11.25",
            "1.11.24",
            "1.11.23",
            "1.11.22",
            "1.11.21",
            "1.11.20",
            "1.11.19",
            "1.11.18",
            "1.11.17",
            "1.11.16",
            "1.11.15",
            "1.11.14",
            "1.11.13",
            "1.11.12",
            "1.11.11",
            "1.11.10",
            "1.11.9",
            "1.11.8",
            "1.11.7",
            "1.11.6",
            "1.11.5",
            "1.11.3",
            "1.11.2",
            "1.11.0",
            "1.10.1",
            "1.10.0",
            "1.9.18",
            "1.9.17",
            "1.9.16",
            "1.9.15",
            "1.10.0-rc1",
            "1.9.14",
            "1.9.13",
            "1.9.12",
            "1.9.11",
            "1.9.10",
            "1.9.9",
            "1.9.8",
            "1.9.7",
            "1.9.6",
            "1.9.5",
            "1.9.4",
            "1.9.3",
            "1.8.8",
            "1.8.7",
            "1.8.6",
            "1.8.5",
            "1.8.4",
            "1.8.3",
            "1.8.2",
            "1.7.24",
            "1.7.23",
            "1.7.22",
            "1.7.21",
            "1.7.20",
            "1.7.19",
            "1.7.18",
            "1.7.17",
            "1.7.16",
            "1.7.15",
            "1.7.11",
            "1.7.10",
            "1.7.9",
            "1.7.8",
            "1.7.7",
            "1.7.6",
            "1.7.5",
            "1.7.4",
            "1.7.3",
            "1.7.1",
            "1.7.0",
            "1.6.1",
            "1.6.0",
            "1.5.13",
            "1.5.12",
            "1.5.11",
            "1.5.10",
            "1.5.9",
            "1.5.8",
            "1.5.7",
            "1.5.6"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2018-20187.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:55.156592235Z",
      "provider": "osv",
      "references": [
        "https://botan.randombit.net/news.html",
        "https://botan.randombit.net/security.html",
        "https://github.com/crocs-muni/ECTester"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2018-20187",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 438351,
  "published_at": "2019-03-08T19:29:00.25+00:00"
}