{"affected":[{"affectedData":[{"product":"Firefox ESR","vendor":"Mozilla","versions":[{"lessThan":"91.5","status":"affected","version":"unspecified","versionType":"custom"}]},{"product":"Firefox","vendor":"Mozilla","versions":[{"lessThan":"96","status":"affected","version":"unspecified","versionType":"custom"}]},{"product":"Thunderbird","vendor":"Mozilla","versions":[{"lessThan":"91.5","status":"affected","version":"unspecified","versionType":"custom"}]}],"source":"security@mozilla.org"}],"configurations":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*","matchCriteriaId":"473CF696-0664-4239-995D-D4700507DD1A","versionEndExcluding":"96.0","vulnerable":true},{"criteria":"cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*","matchCriteriaId":"A8FD4DD9-9B65-49B3-9FED-6FF5085489D2","versionEndExcluding":"91.5","vulnerable":true},{"criteria":"cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*","matchCriteriaId":"A1A101E0-2173-4299-8F05-F325DCDC804B","versionEndExcluding":"91.5","vulnerable":true}],"negate":false,"operator":"OR"}]}],"cveTags":[],"descriptions":[{"lang":"en","value":"It was possible to construct specific XSLT markup that would be able to bypass an iframe sandbox. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5."},{"lang":"es","value":"Fue posible construir un marcado XSLT específico que podría omitir un entorno limitado de iframe. Esta vulnerabilidad afecta a Firefox ESR &lt; 91.5, Firefox &lt; 96 y Thunderbird &lt; 91.5."}],"id":"CVE-2021-4140","lastModified":"2026-06-17T04:19:06.313","metrics":{"cvssMetricV31":[{"cvssData":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":10.0,"baseSeverity":"CRITICAL","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","version":"3.1"},"exploitabilityScore":3.9,"impactScore":6.0,"source":"nvd@nist.gov","type":"Primary"},{"cvssData":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":9.8,"baseSeverity":"CRITICAL","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"exploitabilityScore":3.9,"impactScore":5.9,"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary"}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"id":"CVE-2021-4140","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"total"}],"role":"CISA Coordinator","timestamp":"2025-04-16T15:55:14.536299Z","version":"2.0.3"}}]},"published":"2022-12-22T20:15:12.250","references":[{"source":"security@mozilla.org","tags":["Exploit","Issue Tracking","Patch","Vendor Advisory"],"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1746720"},{"source":"security@mozilla.org","tags":["Vendor Advisory"],"url":"https://www.mozilla.org/security/advisories/mfsa2022-01/"},{"source":"security@mozilla.org","tags":["Vendor Advisory"],"url":"https://www.mozilla.org/security/advisories/mfsa2022-02/"},{"source":"security@mozilla.org","tags":["Vendor Advisory"],"url":"https://www.mozilla.org/security/advisories/mfsa2022-03/"},{"source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Exploit","Issue Tracking","Patch","Vendor Advisory"],"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1746720"},{"source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Vendor Advisory"],"url":"https://www.mozilla.org/security/advisories/mfsa2022-01/"},{"source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Vendor Advisory"],"url":"https://www.mozilla.org/security/advisories/mfsa2022-02/"},{"source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Vendor Advisory"],"url":"https://www.mozilla.org/security/advisories/mfsa2022-03/"}],"sourceIdentifier":"security@mozilla.org","vulnStatus":"Modified","weaknesses":[{"description":[{"lang":"en","value":"CWE-91"}],"source":"nvd@nist.gov","type":"Primary"},{"description":[{"lang":"en","value":"CWE-91"}],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary"}]}