{"id":"CVE-2021-21809","aliases":["BIT-moodle-2021-21809","EUVD-2022-3528","GHSA-c7jj-vfmr-j9mj","UBUNTU-CVE-2021-21809"],"status":"published","title":"Moodle command execution vulnerability exists in the default legacy spellchecker plugin","description":"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.","severity":{"version":"3.0","score":8.2,"vector":"CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:L/A:L","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.24173,"percentile":0.97868,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":true},"cwes":["CWE-732","CWE-78"],"published":"2021-06-23T21:25:46Z","modified":"2026-10-24T10:30:46Z","exploits":[{"source":"metasploit","id":"exploit/multi/http/moodle_spelling_path_rce","title":"Moodle SpellChecker Path Authenticated Remote Command Execution","type":"exploit","platform":"PHP","date":"2021-06-22","verified":true,"url":"https://www.rapid7.com/db/modules/exploit/multi/http/moodle_spelling_path_rce"},{"source":"pocgithub","id":"anldori/CVE-2021-21809","title":"anldori/CVE-2021-21809","date":"2022-12-20","url":"https://github.com/anldori/CVE-2021-21809"}],"fixes":[{"ecosystem":"Bitnami","package":"moodle","fixed_in":["3.10.1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"moodle/moodle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.10.0"},{"last_affected":"3.10.0"}]}],"versions":["3.10.0"]},{"source":"ghsa","ecosystem":"Packagist","package":"moodle/moodle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.11.2"},{"last_affected":"3.11.2"}]}],"versions":["3.11.2"]},{"source":"ghsa","ecosystem":"Packagist","package":"moodle/moodle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.8.0"},{"last_affected":"3.8.0"}]}],"versions":["3.8.0"]},{"source":"osv","ecosystem":"Bitnami","package":"moodle","ranges":[{"type":"SEMVER","events":[{"introduced":"3.10.0"},{"fixed":"3.10.1"}]}]},{"source":"osv","ecosystem":"Packagist","package":"moodle/moodle","versions":["3.10.0"]},{"source":"osv","ecosystem":"Packagist","package":"moodle/moodle","versions":["3.11.2"]},{"source":"osv","ecosystem":"Packagist","package":"moodle/moodle","versions":["3.8.0"]},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"moodle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.7.9+dfsg-1","2.7.10+dfsg-1","2.7.11+dfsg-1","2.7.11+dfsg-2","2.7.12+dfsg-1","3.0.3+dfsg-0ubuntu1","3.0.3+dfsg-0ubuntu1+esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"moodle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.3+dfsg-0ubuntu1","3.0.3+dfsg-0ubuntu1+esm1"]}],"products":[{"vendor":"moodle","product":"moodle"}],"references":[{"url":"https://talosintelligence.com/vulnerability_reports/TALOS-2021-1277","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","advisory","evidence","web","report"]},{"url":"http://packetstormsecurity.com/files/164481/Moodle-SpellChecker-Path-Authenticated-Remote-Command-Execution.html","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","VDB Entry","advisory","evidence","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21809","tags":["web","advisory"]},{"url":"https://github.com/advisories/GHSA-c7jj-vfmr-j9mj"},{"url":"https://github.com/moodle/moodle","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2021-21809","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-21809","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2021-21809","description":"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.","status":"published","published":"2021-06-23T21:25:46Z","modified":"2024-08-03T18:23:29.453Z","cvss":[{"version":"3.0","score":8.2,"vector":"CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:L/A:L","level":"high","assessor":"cna"}],"updated_at":"2026-11-02T14:33:00.488332Z"}],"euvd":[{"id":"EUVD-2022-3528","description":"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. 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An attacker must have administrator privileges to exploit this vulnerabilities.","status":"published","published":"2022-05-24T19:06:04Z","modified":"2024-04-24T17:29:51Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-732"],"updated_at":"2026-11-02T14:37:45.47408Z"}],"nvd":[{"id":"CVE-2021-21809","description":"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.","status":"published","published":"2021-06-23T22:15:08.407Z","modified":"2026-06-17T03:36:09.46Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"3.0","score":8.2,"vector":"CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:L/A:L","level":"high","assessor":"secondary"},{"version":"2.0","score":9,"vector":"AV:N/AC:L/Au:S/C:C/I:C/A:C","level":"high","assessor":"primary"}],"cwes":["CWE-78"],"updated_at":"2026-11-02T14:06:54.892562Z"}],"osv":[{"id":"CVE-2021-21809","description":"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.","status":"published","published":"2021-06-23T22:15:08.407Z","modified":"2026-10-24T10:30:46.029968482Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:44:18.367807Z"},{"id":"GHSA-c7jj-vfmr-j9mj","title":"Moodle command execution vulnerability exists in the default legacy spellchecker plugin","description":"A command execution vulnerability exists in the default legacy spellchecker plugin in a few Moodle multiple specific versions. A specially crafted series of HTTP requests can lead to command execution. An attacker must have administrator privileges to exploit this vulnerabilities.","status":"published","published":"2022-05-24T19:06:04Z","modified":"2024-04-24T17:57:20.400179Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-732"],"updated_at":"2026-11-02T15:46:44.571161Z"},{"id":"UBUNTU-CVE-2021-21809","description":"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.","status":"published","published":"2021-06-23T22:15:00Z","modified":"2026-09-23T18:46:09.826776635Z","cvss":[{"version":"3.0","score":8.2,"vector":"CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:L/A:L","level":"high"},{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:54:26.29421Z"},{"id":"BIT-moodle-2021-21809","description":"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.","status":"published","published":"2024-03-06T11:10:39.111Z","modified":"2026-09-08T08:48:14.746260618Z","updated_at":"2026-11-02T15:28:33.469426Z"}]}}