Security advisory

{
  "id": "bb82951093a0edc04528e18716f9da33f484a743ba807422cf851a5d7354bb4d",
  "url": "https://osv.dev/vulnerability/CVE-2020-21674",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-21674",
    "summary": "Heap-based buffer overflow in archive_string_append_from_wcs() (archive_string.c) in libarchive-3.4.1dev allows remote attackers to cause a denial of service (out-of-bounds write in heap memory resulting into a crash) via a crafted archive file. NOTE: this only affects users who downloaded the development code from GitHub. Users of the product's official releases are unaffected.",
    "evidence": "osv:CVE-2020-21674",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2020-21674",
      "aliases": [
        "CVE-2020-21674"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/libarchive/libarchive",
              "type": "GIT",
              "events": [
                {
                  "introduced": "cce09646b566c61c2debff58a70da780b8457883"
                },
                {
                  "last_affected": "cce09646b566c61c2debff58a70da780b8457883"
                },
                {
                  "fixed": "4f085eea879e2be745f4d9bf57e8513ae48157f4"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:libarchive:libarchive:3.4.1:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.4.1"
                      },
                      {
                        "last_affected": "3.4.1"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "range": [
                      {
                        "fixed": "4f085eea879e2be745f4d9bf57e8513ae48157f4"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "3.4.1",
            "v3.4.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-21674.json",
            "vanir_signatures": [
              {
                "id": "CVE-2020-21674-261c3f39",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
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                },
                "source": "https://github.com/libarchive/libarchive/commit/4f085eea879e2be745f4d9bf57e8513ae48157f4",
                "target": {
                  "file": "libarchive/archive_string.c"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2020-21674-596d9501",
                "digest": {
                  "length": 1087,
                  "function_hash": "291484009972018707314609976661061493870"
                },
                "source": "https://github.com/libarchive/libarchive/commit/4f085eea879e2be745f4d9bf57e8513ae48157f4",
                "target": {
                  "file": "libarchive/archive_string.c",
                  "function": "archive_string_append_from_wcs"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2020-21674-c8b835c7",
                "digest": {
                  "length": 1202,
                  "function_hash": "80370799617205615188298360175217438738"
                },
                "source": "https://github.com/libarchive/libarchive/commit/4f085eea879e2be745f4d9bf57e8513ae48157f4",
                "target": {
                  "file": "libarchive/archive_string.c",
                  "function": "strncat_from_utf8_libarchive2"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              }
            ],
            "vanir_signatures_modified": "2026-10-20T13:55:24Z"
          }
        }
      ],
      "modified": "2026-10-20T13:55:24.775936744Z",
      "provider": "osv",
      "references": [
        "https://github.com/libarchive/libarchive/issues/1298",
        "https://github.com/libarchive/libarchive/commit/4f085eea879e2be745f4d9bf57e8513ae48157f4"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-21674",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 388374,
  "published_at": "2020-10-15T15:15:11.28+00:00"
}