Security advisory

{
  "id": "dda8b8083d7d81f95c9860ef4dd6bede7c4402c85ca28b47441f0c6a1e731611",
  "url": "https://osv.dev/vulnerability/CVE-2021-43398",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-43398",
    "summary": "Crypto++ (aka Cryptopp) 8.6.0 and earlier contains a timing leakage in MakePublicKey(). There is a clear correlation between execution time and private key length, which may cause disclosure of the length information of the private key. This might allow attackers to conduct timing attacks. NOTE: this report is disputed by the vendor and multiple third parties. The execution-time differences are intentional. A user may make a choice of a longer key as a tradeoff between strength and performance. In making this choice, the amount of information leaked to an adversary is of infinitesimal value",
    "evidence": "osv:CVE-2021-43398",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-43398",
      "aliases": [
        "CVE-2021-43398"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/weidai11/cryptopp",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "69bf6b53052b59ccb57ce068ce741988ae087317"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:cryptopp:crypto\\+\\+:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "8.6.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "CRYPTOPP_8_6_0",
            "CRYPTOPP_8_5_0",
            "CRYPTOPP_5_6_2",
            "CRYPTOPP_8_4_0",
            "CRYPTOPP_8_3_0",
            "CRYPTOPP_8_2_0",
            "CRYPTOPP_8_1_0",
            "CRYPTOPP_8_0_0",
            "CRYPTOPP_7_0_0",
            "CRYPTOPP_6_0_0",
            "CRYPTOPP_5_6_5",
            "CRYPTOPP_5_6_4",
            "CRYPTOPP_5_6_3",
            "CRYPTOPP_5_6_1",
            "CRYPTOPP_5_6_0",
            "CRYPTOPP_5_5_2",
            "CRYPTOPP_5_5_1",
            "CRYPTOPP_5_5",
            "CRYPTOPP_5_4",
            "CRYPTOPP_5_3_0",
            "CRYPTOPP_5_2_3",
            "CRYPTOPP_5_2_1",
            "CRYPTOPP_5_2",
            "CRYPTOPP_5_1",
            "CRYPTOPP_5_0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-43398.json"
          }
        }
      ],
      "modified": "2026-10-20T10:55:02.236796265Z",
      "provider": "osv",
      "references": [
        "https://cryptopp.com",
        "https://github.com/weidai11/cryptopp/issues/1080#issuecomment-996492222",
        "https://github.com/weidai11/cryptopp/issues/1080"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-43398",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 386753,
  "published_at": "2021-11-04T21:15:09.52+00:00"
}