{"schemaVersion":3,"id":"USN-5186-1","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"firefox vulnerabilities\n\nMultiple security issues were discovered in Firefox. If a user were\ntricked into opening a specially crafted website, an attacker could\npotentially exploit these to cause a denial of service, obtain sensitive\ninformation, conduct spoofing attacks, bypass CSP restrictions, or\nexecute arbitrary code. (CVE-2021-43536, CVE-2021-43537, CVE-2021-43538,\nCVE-2021-43539, CVE-2021-43541, CVE-2021-43542, CVE-2021-43543,\nCVE-2021-43545, CVE-2021-43546)\n\nA security issue was discovered with the handling of WebExtension\npermissions. If a user were tricked into installing a specially crafted\nextension, an attacker could potentially exploit this to create and\ninstall a service worker that wouldn't be uninstalled with the extension.\n(CVE-2021-43540)","dates":{"published":"2021-12-09T18:55:33.000Z","modified":"2026-04-22T10:18:48.138Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":null,"severity":"unknown","version":null,"versionLabel":null,"source":null,"vector":null,"computed":false,"selection":"none"},"metrics":[]},"epss":{"probability":null,"percentile":null,"severity":"unknown","asOf":null,"change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[],"last30":[]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[],"affected":[{"vendor":"ubuntu","product":"firefox","name":"firefox","label":"firefox","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/firefox","purlType":"deb","versions":[{"text":"< 95.0+build1-0ubuntu0.18.04.1","noFixRecorded":false,"fixedIn":null},{"text":"< 95.0+build1-0ubuntu0.20.04.1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 95.0+build1-0ubuntu0.18.04.1 | < 95.0+build1-0ubuntu0.20.04.1","eol":null,"hubHref":null}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://ubuntu.com/security/notices/USN-5186-1","label":"ubuntu.com/security/notices/USN-5186-1","hostname":"ubuntu.com","tags":["Advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-43536","label":"ubuntu.com/security/CVE-2021-43536","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-43537","label":"ubuntu.com/security/CVE-2021-43537","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-43538","label":"ubuntu.com/security/CVE-2021-43538","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-43539","label":"ubuntu.com/security/CVE-2021-43539","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-43540","label":"ubuntu.com/security/CVE-2021-43540","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-43541","label":"ubuntu.com/security/CVE-2021-43541","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-43542","label":"ubuntu.com/security/CVE-2021-43542","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-43543","label":"ubuntu.com/security/CVE-2021-43543","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-43545","label":"ubuntu.com/security/CVE-2021-43545","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-43546","label":"ubuntu.com/security/CVE-2021-43546","hostname":"ubuntu.com","tags":["REPORT"]}],"lineage":{"upstream":["CVE-2021-43536","CVE-2021-43537","CVE-2021-43538","CVE-2021-43539","CVE-2021-43540","CVE-2021-43541","CVE-2021-43542","CVE-2021-43543","CVE-2021-43545","CVE-2021-43546"],"downstream":[],"duplicates":[],"related":["CVE-2021-43536","CVE-2021-43537","CVE-2021-43538","CVE-2021-43539","CVE-2021-43540","CVE-2021-43541","CVE-2021-43542","CVE-2021-43543","CVE-2021-43545","CVE-2021-43546"]},"timeline":[{"kind":"published","date":"2021-12-09T18:55:33.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-04-22T10:18:48.138Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":0,"level":"minimal","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-20T16:16:54.559Z","stale":false,"partial":false}}