{"schemaVersion":3,"id":"USN-4926-1","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, spoof the\nbrowser UI, bypass security restrictions, trick the user into disclosing\nconfidential information, or execute arbitrary code. (CVE-2021-23994,\nCVE-2021-23996, CVE-2021-23997, CVE-2021-23998, CVE-2021-23999,\nCVE-2021-24000, CVE-2021-24001, CVE-2021-29945, CVE-2021-29946,\nCVE-2021-29947)\n\nA use-after-free was discovered when Responsive Design Mode was\nenabled. If a user were tricked into opening a specially crafted\nwebsite with Responsive Design Mode enabled, an attacker could\npotentially exploit this to cause a denial of service, or execute\narbitrary code. (CVE-2021-23995)\n\nIt was discovered that Firefox mishandled ftp URLs with encoded newline\ncharacters. If a user were tricked into clicking on a specially crafted\nlink, an attacker could potentially exploit this to send arbitrary\nFTP commands. (CVE-2021-24002)","dates":{"published":"2021-04-26T10:44:42.000Z","modified":"2026-04-22T10:14:26.868Z","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":"< 88.0+build2-0ubuntu0.16.04.1","noFixRecorded":false,"fixedIn":null},{"text":"< 88.0+build2-0ubuntu0.18.04.2","noFixRecorded":false,"fixedIn":null},{"text":"< 88.0+build2-0ubuntu0.20.04.1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 88.0+build2-0ubuntu0.16.04.1 | < 88.0+build2-0ubuntu0.18.04.2 | < 88.0+build2-0ubuntu0.20.04.1","eol":null,"hubHref":null}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://ubuntu.com/security/notices/USN-4926-1","label":"ubuntu.com/security/notices/USN-4926-1","hostname":"ubuntu.com","tags":["Advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-23994","label":"ubuntu.com/security/CVE-2021-23994","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23995","label":"ubuntu.com/security/CVE-2021-23995","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23996","label":"ubuntu.com/security/CVE-2021-23996","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23997","label":"ubuntu.com/security/CVE-2021-23997","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23998","label":"ubuntu.com/security/CVE-2021-23998","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23999","label":"ubuntu.com/security/CVE-2021-23999","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-24000","label":"ubuntu.com/security/CVE-2021-24000","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-24001","label":"ubuntu.com/security/CVE-2021-24001","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-24002","label":"ubuntu.com/security/CVE-2021-24002","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-29945","label":"ubuntu.com/security/CVE-2021-29945","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-29946","label":"ubuntu.com/security/CVE-2021-29946","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-29947","label":"ubuntu.com/security/CVE-2021-29947","hostname":"ubuntu.com","tags":["REPORT"]}],"lineage":{"upstream":["CVE-2021-23994","CVE-2021-23995","CVE-2021-23996","CVE-2021-23997","CVE-2021-23998","CVE-2021-23999","CVE-2021-24000","CVE-2021-24001","CVE-2021-24002","CVE-2021-29945","CVE-2021-29946","CVE-2021-29947"],"downstream":[],"duplicates":[],"related":["CVE-2021-23994","CVE-2021-23995","CVE-2021-23996","CVE-2021-23997","CVE-2021-23998","CVE-2021-23999","CVE-2021-24000","CVE-2021-24001","CVE-2021-24002","CVE-2021-29945","CVE-2021-29946","CVE-2021-29947"]},"timeline":[{"kind":"published","date":"2021-04-26T10:44:42.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-04-22T10:14:26.868Z","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":"2026-10-20T08:12:13.060Z","stale":false,"partial":false}}