{"id":"CVE-2021-30665","kind":"vulnerability","aliases":["CVE-2021-30665"],"related":[],"title":"Apple Multiple Products: Apple Multiple Products WebKit Memory Corruption Vulnerability","description":"Apple iOS, iPadOS, macOS, watchOS, and tvOS WebKit contain a memory corruption vulnerability that leads to code execution when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.\n\nCISA required action: Apply updates per vendor instructions.","summary":"A memory corruption bug in Apple's WebKit engine lets a crafted web page run code when it is processed. It is listed as exploited in the wild, so attackers have used it.","severity":"high","cvss":8.8,"epss":0.03706,"exploited":true,"exploited_at":"2021-11-03T00:00:00+00:00","products":[{"name":"Apple Multiple Products","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["apple","exploited","ios","macos","safari","vendor","webkit"],"not_affected_if":["unpatched-builds-only"],"how_to_check":null,"fix":"Update iOS, iPadOS, macOS, watchOS and tvOS to a patched Apple release per vendor instructions. Fixed versions are not stated in the sources.","status":"open","published_at":"2021-09-08T15:15:13+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T21:33:58+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"vendor","confidence":0.6,"triage":{"at":"2026-10-23T21:33:58Z","model":"claude-haiku-5-5","output":{"fix":"Update iOS, iPadOS, macOS, watchOS and tvOS to a patched Apple release per vendor instructions. Fixed versions are not stated in the sources.","reach":"internet","impact":"high","summary":"A memory corruption bug in Apple's WebKit engine lets a crafted web page run code when it is processed. It is listed as exploited in the wild, so attackers have used it.","category":"vendor","who_cares":["apple","ios","macos","safari","webkit"],"confidence":0.6,"needs_auth":"no","worst_case":"Attacker runs code on the device after the victim opens malicious web content","analyst_note":"Find the Apple security advisory for CVE-2021-30665 and the exact patched OS versions to fill in fix and how_to_check.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["unpatched-builds-only"],"user_interaction":"yes","needs_special_setup":"no","severity_if_unknown":"high"},"cost_usd":0.000461,"input_tokens":2904,"output_tokens":342,"severity_before":"unknown"},"analyst_status":"queued","analyst_note":"Find the Apple security advisory for CVE-2021-30665 and the exact patched OS versions to fill in fix and how_to_check.","search":"'-2021':12A,15A '-30665':13A,16A 'action':113C 'appl':1A,4A,20B,32B,59C,97C,102C 'apple':17A 'appli':114C 'attack':56B 'bug':30B 'cisa':111C 'code':42B,75C 'contain':67C 'content':82C 'corrupt':9A,29B,70C 'could':85C 'craft':38B,80C 'cve':11A,14A 'engin':35B 'execut':76C 'exploit':21B,51B 'html':87C,109C 'impact':86C 'includ':92C 'instruct':118C 'io':22B,60C 'ipado':61C 'lead':73C 'let':36B 'limit':95C 'list':49B 'maco':23B,62C 'malici':79C 'memori':8A,28B,69C 'multipl':2A,5A 'multiple':18A 'non':101C 'non-appl':100C 'page':40B 'parser':88C 'per':116C 'process':46B,78C,110C 'product':3A,6A,103C 'products':19A 'reli':105C 'requir':112C 'run':41B 'safari':24B,98C 'tvos':65C 'updat':115C 'use':58B,90C 'vendor':25B,117C 'vulner':10A,71C,84C 'watcho':63C 'web':39B,81C 'webkit':7A,26B,34B,66C,91C,107C 'wild':54B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2021-09-08T15:15:13+00:00","kev":{"dateAdded":"2021-11-03","dueDate":"2021-11-17","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2021-30665","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-30665","severity":null,"published_at":"2021-11-03T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:53+00:00","fetched_at":"2026-10-25T21:35:52+00:00","note":null},{"source":"epss","external_id":"CVE-2021-30665","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-30665","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:44+00:00","fetched_at":"2026-10-23T19:13:44+00:00","note":null},{"source":"nvd","external_id":"CVE-2021-30665","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-30665","severity":null,"published_at":"2021-09-08T15:15:13+00:00","modified_at":"2026-06-17T03:50:39+00:00","first_seen_at":"2026-10-23T21:57:35+00:00","fetched_at":"2026-10-23T21:57:35+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}