{"id":"CVE-2021-30663","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-30663","generatedAt":"2026-10-31T14:14:26.831Z","title":"Apple Multiple Products WebKit Integer Overflow Vulnerability","description":"An integer overflow was addressed with improved input validation. This issue is fixed in iOS 14.5.1 and iPadOS 14.5.1, tvOS 14.6, iOS 12.5.3, Safari 14.1.1, macOS Big Sur 11.3.1. Processing maliciously crafted web content may lead to arbitrary code execution.","published":"2021-09-08T15:15:13.000Z","lastModified":"2026-06-17T03:50:39.000Z","status":"Analyzed","sourceIdentifier":"product-security@apple.com","cvss":{"version":"3.1","score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"},"cwe":["CWE-190"],"affected":["apple/safari","apple/ipados","apple/iphone os","apple/macos","apple/tvos"],"epss":{"score":0.03521,"percentile":0.89215,"date":"2026-10-30","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-2021-30663"},"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/HT212335","tags":["Release Notes","Vendor Advisory"],"source":"product-security@apple.com"},{"url":"https://support.apple.com/en-us/HT212336","tags":["Release Notes","Vendor Advisory"],"source":"product-security@apple.com"},{"url":"https://support.apple.com/en-us/HT212341","tags":["Release Notes","Vendor Advisory"],"source":"product-security@apple.com"},{"url":"https://support.apple.com/en-us/HT212532","tags":["Release Notes","Vendor Advisory"],"source":"product-security@apple.com"},{"url":"https://support.apple.com/en-us/HT212534","tags":["Release Notes","Vendor Advisory"],"source":"product-security@apple.com"},{"url":"https://support.apple.com/en-us/HT212335","tags":["Release Notes","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/en-us/HT212336","tags":["Release Notes","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/en-us/HT212341","tags":["Release Notes","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/en-us/HT212532","tags":["Release Notes","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.apple.com/en-us/HT212534","tags":["Release Notes","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30663","tags":["Third Party Advisory","US Government Resource"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-30663","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."}