Security advisory

{
  "id": "21a3669420a021c2b48d1e1dac29038173708b8db9ac0f2c59a750b16a76bb96",
  "url": "https://osv.dev/vulnerability/CVE-2021-20729",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-20729",
    "summary": "Cross-site scripting vulnerability in pfSense CE and pfSense Plus (pfSense CE software versions 2.5.2 and earlier, and pfSense Plus software versions 21.05 and earlier) allows a remote attacker to inject an arbitrary script via a malicious URL.",
    "evidence": "osv:CVE-2021-20729",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-20729",
      "aliases": [
        "CVE-2021-20729"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/pfsense/pfsense",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "81891ef87be63352e1c32d28ca9fc08bbf641989"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:pfsense:pfsense:*:*:*:*:community:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "2.5.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.5.2",
            "RELENG_2_2_BETA",
            "Root_RELENG_1_2"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-20729.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:55.717650298Z",
      "provider": "osv",
      "references": [
        "https://docs.netgate.com/downloads/pfSense-SA-21_02.captiveportal.asc",
        "https://jvn.jp/en/jp/JVN87751554/index.html"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:a:netgate:pfsense_plus:*:*:*:*:*:*:*:*"
            ],
            "vendor_product": "netgate:pfsense_plus",
            "extracted_events": [
              {
                "range": [
                  {
                    "last_affected": "21.05"
                  }
                ],
                "source": "CPE_RANGE"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2021-20729",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 438483,
  "published_at": "2022-03-31T08:15:08.13+00:00"
}