Security advisory

{
  "id": "7c2ae2b3ac28c994718b38d3fcf163b3745548993171fa6a1ff0328c6fb11682",
  "url": "https://osv.dev/vulnerability/CVE-2020-21840",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-21840",
    "summary": "A heap based buffer overflow vulnerability exits in GNU LibreDWG 0.10 via bit_search_sentinel ../../src/bits.c:1985.",
    "evidence": "osv:CVE-2020-21840",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2020-21840",
      "aliases": [
        "CVE-2020-21840"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/libredwg/libredwg",
              "type": "GIT",
              "events": [
                {
                  "introduced": "d5a51c01023d5585ddf3dd17c83dbb3c81efc97e"
                },
                {
                  "last_affected": "d5a51c01023d5585ddf3dd17c83dbb3c81efc97e"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:gnu:libredwg:0.10:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0.10"
                      },
                      {
                        "last_affected": "0.10"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.10"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-21840.json"
          }
        }
      ],
      "modified": "2026-10-20T10:52:11.986673630Z",
      "provider": "osv",
      "references": [
        "https://github.com/LibreDWG/libredwg/issues/188#issuecomment-574493513"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-21840",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 383456,
  "published_at": "2021-05-17T21:15:07.557+00:00"
}