{"api_version":"1","generated_at":"2026-04-22T23:31:13+00:00","cve":"CVE-2021-38509","urls":{"html":"https://cve.report/CVE-2021-38509","api":"https://cve.report/api/cve/CVE-2021-38509.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-38509","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-38509"},"summary":{"title":"CVE-2021-38509","description":"Due to an unusual sequence of attacker-controlled events, a Javascript alert() dialog with arbitrary (although unstyled) contents could be displayed over top an uncontrolled webpage of the attacker's choosing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.","state":"PUBLIC","assigner":"security@mozilla.org","published_at":"2021-12-08 22:15:00","updated_at":"2022-12-09 15:22:00"},"problem_types":["CWE-1021"],"metrics":[],"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1718571","name":"https://bugzilla.mozilla.org/show_bug.cgi?id=1718571","refsource":"MISC","tags":[],"title":"Access Denied","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://www.debian.org/security/2021/dsa-5026","name":"DSA-5026","refsource":"DEBIAN","tags":[],"title":"Debian -- Security Information -- DSA-5026-1 firefox-esr","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://www.mozilla.org/security/advisories/mfsa2021-50/","name":"https://www.mozilla.org/security/advisories/mfsa2021-50/","refsource":"MISC","tags":[],"title":"Security Vulnerabilities fixed in Thunderbird 91.3 — Mozilla","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://security.gentoo.org/glsa/202208-14","name":"GLSA-202208-14","refsource":"GENTOO","tags":[],"title":"Mozilla Thunderbird: Multiple Vulnerabilities (GLSA 202208-14) — Gentoo security","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://www.mozilla.org/security/advisories/mfsa2021-48/","name":"https://www.mozilla.org/security/advisories/mfsa2021-48/","refsource":"MISC","tags":[],"title":"Security Vulnerabilities fixed in Firefox 94 — Mozilla","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://www.mozilla.org/security/advisories/mfsa2021-49/","name":"https://www.mozilla.org/security/advisories/mfsa2021-49/","refsource":"MISC","tags":[],"title":"Security Vulnerabilities fixed in Firefox ESR 91.3 — Mozilla","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://security.gentoo.org/glsa/202202-03","name":"GLSA-202202-03","refsource":"GENTOO","tags":[],"title":"Mozilla Firefox: Multiple vulnerabilities (GLSA 202202-03) — Gentoo security","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://www.debian.org/security/2022/dsa-5034","name":"DSA-5034","refsource":"DEBIAN","tags":[],"title":"Debian -- Security Information -- DSA-5034-1 thunderbird","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html","name":"[debian-lts-announce] 20211229 [SECURITY] [DLA 2863-1] firefox-esr security update","refsource":"MLIST","tags":[],"title":"[SECURITY] [DLA 2863-1] firefox-esr security update","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html","name":"[debian-lts-announce] 20220104 [SECURITY] [DLA 2874-1] thunderbird security update","refsource":"MLIST","tags":[],"title":"[SECURITY] [DLA 2874-1] thunderbird security update","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-38509","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-38509","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2021","cve_id":"38509","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"debian","cpe5":"debian_linux","cpe6":"10.0","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"38509","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"debian","cpe5":"debian_linux","cpe6":"11.0","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"38509","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"debian","cpe5":"debian_linux","cpe6":"9.0","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"38509","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"mozilla","cpe5":"firefox","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"38509","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"mozilla","cpe5":"firefox_esr","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"38509","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"mozilla","cpe5":"thunderbird","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[{"cve":"CVE-2021-38509","qid":"159449","title":"Oracle Enterprise Linux Security Update for firefox (ELSA-2021-4116)"},{"cve":"CVE-2021-38509","qid":"159450","title":"Oracle Enterprise Linux Security Update for firefox (ELSA-2021-4123)"},{"cve":"CVE-2021-38509","qid":"159451","title":"Oracle Enterprise Linux Security Update for thunderbird (ELSA-2021-4130)"},{"cve":"CVE-2021-38509","qid":"159452","title":"Oracle Enterprise Linux Security Update for thunderbird (ELSA-2021-4134)"},{"cve":"CVE-2021-38509","qid":"178948","title":"Debian Security Update for firefox-esr (DSA 5026-1)"},{"cve":"CVE-2021-38509","qid":"178970","title":"Debian Security Update for firefox-esr (DLA 2863-1)"},{"cve":"CVE-2021-38509","qid":"178983","title":"Debian Security Update for thunderbird (DSA 5034-1)"},{"cve":"CVE-2021-38509","qid":"178986","title":"Debian Security Update for thunderbird (DLA 2874-1)"},{"cve":"CVE-2021-38509","qid":"180428","title":"Debian Security Update for firefox-esr (CVE-2021-38509)"},{"cve":"CVE-2021-38509","qid":"198556","title":"Ubuntu Security Notification for Firefox Vulnerabilities (USN-5131-1)"},{"cve":"CVE-2021-38509","qid":"198581","title":"Ubuntu Security Notification for Thunderbird Vulnerabilities (USN-5152-1)"},{"cve":"CVE-2021-38509","qid":"198641","title":"Ubuntu Security Notification for Thunderbird Vulnerabilities (USN-5248-1)"},{"cve":"CVE-2021-38509","qid":"239773","title":"Red Hat Update for firefox (RHSA-2021:4116)"},{"cve":"CVE-2021-38509","qid":"239774","title":"Red Hat Update for thunderbird (RHSA-2021:4133)"},{"cve":"CVE-2021-38509","qid":"239775","title":"Red Hat Update for thunderbird (RHSA-2021:4130)"},{"cve":"CVE-2021-38509","qid":"239776","title":"Red Hat Update for thunderbird (RHSA-2021:4134)"},{"cve":"CVE-2021-38509","qid":"239777","title":"Red Hat Update for firefox (RHSA-2021:4123)"},{"cve":"CVE-2021-38509","qid":"239778","title":"Red Hat Update for thunderbird (RHSA-2021:4132)"},{"cve":"CVE-2021-38509","qid":"239853","title":"Red Hat Update for firefox (RHSA-2021:4605)"},{"cve":"CVE-2021-38509","qid":"239860","title":"Red Hat Update for firefox (RHSA-2021:4607)"},{"cve":"CVE-2021-38509","qid":"257117","title":"CentOS Security Update for thunderbird (CESA-2021:4134)"},{"cve":"CVE-2021-38509","qid":"257118","title":"CentOS Security Update for firefox (CESA-2021:4116)"},{"cve":"CVE-2021-38509","qid":"296066","title":"Oracle Solaris 11.4 Support Repository Update (SRU) 40.107.3 Missing (CPUOCT2021)"},{"cve":"CVE-2021-38509","qid":"376014","title":"Mozilla Firefox ESR Multiple Vulnerabilities (MFSA2021-49)"},{"cve":"CVE-2021-38509","qid":"376015","title":"Mozilla Firefox Multiple Vulnerabilities (MFSA2021-48)"},{"cve":"CVE-2021-38509","qid":"376038","title":"Mozilla Thunderbird Multiple Vulnerabilities (MFSA2021-50)"},{"cve":"CVE-2021-38509","qid":"502070","title":"Alpine Linux Security Update for firefox-esr"},{"cve":"CVE-2021-38509","qid":"502082","title":"Alpine Linux Security Update for firefox"},{"cve":"CVE-2021-38509","qid":"502381","title":"Alpine Linux Security Update for thunderbird"},{"cve":"CVE-2021-38509","qid":"503632","title":"Alpine Linux Security Update for thunderbird"},{"cve":"CVE-2021-38509","qid":"503634","title":"Alpine Linux Security Update for thunderbird"},{"cve":"CVE-2021-38509","qid":"503650","title":"Alpine Linux Security Update for thunderbird"},{"cve":"CVE-2021-38509","qid":"503669","title":"Alpine Linux Security Update for thunderbird"},{"cve":"CVE-2021-38509","qid":"503853","title":"Alpine Linux Security Update for firefox"},{"cve":"CVE-2021-38509","qid":"506260","title":"Alpine Linux Security Update for thunderbird"},{"cve":"CVE-2021-38509","qid":"710574","title":"Gentoo Linux Mozilla Firefox Multiple Vulnerabilities (GLSA 202202-03)"},{"cve":"CVE-2021-38509","qid":"710585","title":"Gentoo Linux Mozilla Thunderbird Multiple Vulnerabilities (GLSA 202208-14)"},{"cve":"CVE-2021-38509","qid":"751360","title":"SUSE Enterprise Linux Security Update for MozillaFirefox (SUSE-SU-2021:3651-1)"},{"cve":"CVE-2021-38509","qid":"751371","title":"OpenSUSE Security Update for MozillaFirefox (openSUSE-SU-2021:3745-1)"},{"cve":"CVE-2021-38509","qid":"751387","title":"SUSE Enterprise Linux Security Update for MozillaFirefox (SUSE-SU-2021:3721-1)"},{"cve":"CVE-2021-38509","qid":"751542","title":"OpenSUSE Security Update for MozillaThunderbird (openSUSE-SU-2021:4150-1)"},{"cve":"CVE-2021-38509","qid":"751566","title":"OpenSUSE Security Update for MozillaThunderbird (openSUSE-SU-2021:1635-1)"},{"cve":"CVE-2021-38509","qid":"940017","title":"AlmaLinux Security Update for thunderbird (ALSA-2021:4130)"},{"cve":"CVE-2021-38509","qid":"940364","title":"AlmaLinux Security Update for firefox (ALSA-2021:4123)"},{"cve":"CVE-2021-38509","qid":"960054","title":"Rocky Linux Security Update for firefox (RLSA-2021:4123)"},{"cve":"CVE-2021-38509","qid":"960744","title":"Rocky Linux Security Update for thunderbird (RLSA-2021:4130)"}]},"source_records":{"cve_program":{"data_type":"CVE","data_format":"MITRE","data_version":"4.0","CVE_data_meta":{"ID":"CVE-2021-38509","ASSIGNER":"security@mozilla.org","STATE":"PUBLIC"},"affects":{"vendor":{"vendor_data":[{"vendor_name":"Mozilla","product":{"product_data":[{"product_name":"Firefox","version":{"version_data":[{"version_value":"94","version_affected":"<"}]}},{"product_name":"Thunderbird","version":{"version_data":[{"version_value":"91.3","version_affected":"<"}]}},{"product_name":"Firefox ESR","version":{"version_data":[{"version_value":"91.3","version_affected":"<"}]}}]}}]}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"Javascript alert box could have been spoofed onto an arbitrary domain"}]}]},"references":{"reference_data":[{"url":"https://www.mozilla.org/security/advisories/mfsa2021-49/","refsource":"MISC","name":"https://www.mozilla.org/security/advisories/mfsa2021-49/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2021-50/","refsource":"MISC","name":"https://www.mozilla.org/security/advisories/mfsa2021-50/"},{"url":"https://www.mozilla.org/security/advisories/mfsa2021-48/","refsource":"MISC","name":"https://www.mozilla.org/security/advisories/mfsa2021-48/"},{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1718571","refsource":"MISC","name":"https://bugzilla.mozilla.org/show_bug.cgi?id=1718571"},{"refsource":"DEBIAN","name":"DSA-5026","url":"https://www.debian.org/security/2021/dsa-5026"},{"refsource":"MLIST","name":"[debian-lts-announce] 20211229 [SECURITY] [DLA 2863-1] firefox-esr security update","url":"https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html"},{"refsource":"DEBIAN","name":"DSA-5034","url":"https://www.debian.org/security/2022/dsa-5034"},{"refsource":"MLIST","name":"[debian-lts-announce] 20220104 [SECURITY] [DLA 2874-1] thunderbird security update","url":"https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html"},{"refsource":"GENTOO","name":"GLSA-202202-03","url":"https://security.gentoo.org/glsa/202202-03"},{"refsource":"GENTOO","name":"GLSA-202208-14","url":"https://security.gentoo.org/glsa/202208-14"}]},"description":{"description_data":[{"lang":"eng","value":"Due to an unusual sequence of attacker-controlled events, a Javascript alert() dialog with arbitrary (although unstyled) contents could be displayed over top an uncontrolled webpage of the attacker's choosing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3."}]}},"nvd":{"publishedDate":"2021-12-08 22:15:00","lastModifiedDate":"2022-12-09 15:22:00","problem_types":["CWE-1021"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"NONE","baseScore":4.3,"baseSeverity":"MEDIUM"},"exploitabilityScore":2.8,"impactScore":1.4},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:M/Au:N/C:N/I:P/A:N","accessVector":"NETWORK","accessComplexity":"MEDIUM","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"PARTIAL","availabilityImpact":"NONE","baseScore":4.3},"severity":"MEDIUM","exploitabilityScore":8.6,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":true}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*","versionEndExcluding":"91.3.0","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*","versionEndExcluding":"91.3.0","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*","versionEndExcluding":"94.0","cpe_name":[]}]},{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"38509","Ordinal":"214171","Title":"CVE-2021-38509","CVE":"CVE-2021-38509","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"38509","Ordinal":"1","NoteData":"Due to an unusual sequence of attacker-controlled events, a Javascript alert() dialog with arbitrary (although unstyled) contents could be displayed over top an uncontrolled webpage of the attacker's choosing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.","Type":"Description","Title":null},{"CveYear":"2021","CveId":"38509","Ordinal":"2","NoteData":"2021-12-08","Type":"Other","Title":"Published"},{"CveYear":"2021","CveId":"38509","Ordinal":"3","NoteData":"2022-01-04","Type":"Other","Title":"Modified"}]}}}