Security advisory

{
  "id": "b0113fa9be77a47c672d1dd569b5559c98e5d956e579e680f6d8db21dc2c7487",
  "url": "https://osv.dev/vulnerability/CVE-2021-20308",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-20308",
    "summary": "Integer overflow in the htmldoc 1.9.11 and before may allow attackers to execute arbitrary code and cause a denial of service that is similar to CVE-2017-9181.",
    "evidence": "osv:CVE-2021-20308",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2021-20308",
      "aliases": [
        "CVE-2021-20308"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/michaelrsweet/htmldoc",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "5229002a38f111169974e9df2da75de95c1996ca"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:htmldoc_project:htmldoc:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.9.11"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.9.11",
            "v1.9.10",
            "v1.9.9",
            "v1.9.8",
            "v1.9.7",
            "v1.9.6",
            "v1.9.5",
            "v1.9.4",
            "v1.9.3",
            "v1.9.2",
            "v1.9.1",
            "v1.9",
            "v1.8.30"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-20308.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:27.125351465Z",
      "provider": "osv",
      "references": [
        "https://lists.debian.org/debian-lts-announce/2021/07/msg00000.html",
        "https://bugzilla.redhat.com/show_bug.cgi?id=1946289",
        "https://github.com/michaelrsweet/htmldoc/issues/423"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*"
            ],
            "vendor_product": "debian:debian_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "9.0"
                  },
                  {
                    "last_affected": "9.0"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2021-20308",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 385374,
  "published_at": "2021-04-05T22:15:12.947+00:00"
}