Security advisory

{
  "id": "9110a1e051e349920d9dd498d5128d89b8869de089108c1edabc365cb01f9b0f",
  "url": "https://osv.dev/vulnerability/CVE-2021-21809",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-21809",
    "summary": "A command execution vulnerability exists in the default legacy spellchecker plugin in Moodle 3.10. A specially crafted series of HTTP requests can lead to command execution. An attacker must have administrator privileges to exploit this vulnerabilities.",
    "evidence": "osv:CVE-2021-21809",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2021-21809",
      "aliases": [
        "BIT-moodle-2021-21809",
        "CVE-2021-21809",
        "GHSA-c7jj-vfmr-j9mj"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/moodle/moodle",
              "type": "GIT",
              "events": [
                {
                  "introduced": "ec58cefefb2722f61f77c9a2b6a12d40a8c078a0"
                },
                {
                  "last_affected": "ec58cefefb2722f61f77c9a2b6a12d40a8c078a0"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:moodle:moodle:3.10.0:-:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.10.0-NA"
                      },
                      {
                        "last_affected": "3.10.0-NA"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "3.10.0-NA",
            "v3.10.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-21809.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:46.029968482Z",
      "provider": "osv",
      "references": [
        "https://talosintelligence.com/vulnerability_reports/TALOS-2021-1277"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-21809",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 436248,
  "published_at": "2021-06-23T22:15:08.407+00:00"
}