{"id":"CVE-2021-21809","aliases":["BIT-moodle-2021-21809","GHSA-c7jj-vfmr-j9mj"],"url":"https://o3.security/vulnerability/CVE-2021-21809","summary":"Moodle command execution vulnerability exists in the default legacy spellchecker plugin","details":"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.","published":"2021-06-23T22:15:08.407Z","modified":"2026-07-09T01:30:10.685591Z","cvss":{"score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":3,"affectedPackages":[{"ecosystem":"Packagist","name":"moodle/moodle","fixedVersion":null},{"ecosystem":"Packagist","name":"moodle/moodle","fixedVersion":null},{"ecosystem":"Packagist","name":"moodle/moodle","fixedVersion":null}],"fix":null,"references":[{"type":"EVIDENCE","url":"http://packetstormsecurity.com/files/164481/Moodle-SpellChecker-Path-Authenticated-Remote-Command-Execution.html"},{"type":"EVIDENCE","url":"https://talosintelligence.com/vulnerability_reports/TALOS-2021-1277"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T01:30:10.685591Z"}}