{"id":"CVE-2021-1879","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-1879","generatedAt":"2026-10-27T21:19:05.166Z","title":"Apple iOS, iPadOS, and watchOS WebKit Cross-Site Scripting (XSS) Vulnerability","description":"This issue was addressed by improved management of object lifetimes. This issue is fixed in iOS 12.5.2, iOS 14.4.2 and iPadOS 14.4.2, watchOS 7.3.3. Processing maliciously crafted web content may lead to universal cross site scripting. Apple is aware of a report that this issue may have been actively exploited..","published":"2021-04-02T19:15:21.000Z","lastModified":"2026-06-17T03:32:43.000Z","status":"Analyzed","sourceIdentifier":"product-security@apple.com","cvss":{"version":"3.1","score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"cwe":["CWE-79"],"affected":["apple/ipados","apple/iphone os","apple/watchos"],"epss":{"score":0.07082,"percentile":0.94177,"date":"2026-10-26","history":[]},"kev":{"listed":true,"dateAdded":"2021-11-03","dueDate":"2021-11-17","knownRansomwareCampaignUse":"Unknown","notes":"Apply updates per vendor instructions.\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-1879"},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"Known to be exploited in the wild (CISA KEV, CISA remediation deadline 17 November 2021). Treat as an emergency change: patch or isolate now, then hunt for prior compromise."},"changes":[],"references":[{"url":"https://support.apple.com/en-us/HT212256","tags":["Release Notes","Vendor Advisory"],"source":"product-security@apple.com"},{"url":"https://support.apple.com/en-us/HT212257","tags":["Release Notes","Vendor Advisory"],"source":"product-security@apple.com"},{"url":"https://support.apple.com/en-us/HT212258","tags":["Release Notes","Vendor Advisory"],"source":"product-security@apple.com"},{"url":"https://support.apple.com/en-us/HT212256","tags":["Release Notes","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/en-us/HT212257","tags":["Release Notes","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/en-us/HT212258","tags":["Release Notes","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1879","tags":["US Government Resource"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-1879","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}