{"id":"CVE-2021-1789","published":"2021-04-02T18:15:21Z","modified":"2026-06-17T03:32:33Z","title":"Apple Multiple Products Type Confusion Vulnerability","vendor":"Apple","product":"Multiple Products","tier":"core","eol":null,"description":{"text":"A type confusion issue was addressed with improved state handling. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. Processing maliciously crafted web content may lead to arbitrary code execution.","provenance":"source","from":"NVD"},"summary":{"text":"The flaw is a type confusion vulnerability in multiple Apple products, addressed through improved state handling, affecting macOS Big Sur, macOS Catalina and Mojave security updates, tvOS, watchOS, iOS, iPadOS and Safari. An attacker can achieve arbitrary code execution by getting a user to process maliciously crafted web content, requiring network access and user interaction with no prior authentication.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-31T05:10:29Z"},"cvss":{"score":8.8,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.13975,"percentile":0.96546,"date":"2026-10-30","provenance":"source"},"kev":{"dateAdded":"2022-05-04","dueDate":"2022-05-25","ransomware":false,"requiredAction":"Apply updates per vendor instructions.","notes":"https://nvd.nist.gov/vuln/detail/CVE-2021-1789","provenance":"source"},"vulncheckKev":{"dateAdded":"2021-10-11","exploitedFirstSeen":"2021-10-11","ransomware":false,"evidence":[{"url":"https://blog.google/threat-analysis-group/analyzing-watering-hole-campaign-using-macos-exploits/","date":"2021-10-11"},{"url":"https://www.welivesecurity.com/2022/01/25/watering-hole-deploys-new-macos-malware-dazzlespy-asia/","date":"2022-01-25"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2022-05-04"},{"url":"https://objective-see.org/blog/blog_0x71.html","date":"2023-01-01"},{"url":"https://www.group-ib.com/resources/research-hub/hi-tech-crime-trends-2022/","date":"2023-01-17"}],"evidenceTotal":5,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 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2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-843","name":"Access of Resource Using Incompatible Type"}],"references":[{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN6ZOD62CTO54CHTMJTHVEF6R2Y532TJ/","tags":["Broken Link","Mailing List"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/","tags":["Broken Link","Mailing List"]},{"url":"https://security.gentoo.org/glsa/202104-03","tags":["Third Party Advisory"]},{"url":"https://support.apple.com/en-us/HT212146","tags":["Release 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Advisory"]},{"url":"https://support.apple.com/en-us/HT212147","tags":["Release Notes","Vendor Advisory"]},{"url":"https://support.apple.com/en-us/HT212148","tags":["Release Notes","Vendor Advisory"]},{"url":"https://support.apple.com/en-us/HT212149","tags":["Release Notes","Vendor Advisory"]},{"url":"https://support.apple.com/en-us/HT212152","tags":["Release Notes","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1789","tags":["US Government Resource"]}],"techniques":[{"id":"T1189","name":"Drive-by Compromise","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Malicious web content delivered to victim browsers","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"Processing maliciously crafted web content may lead to arbitrary code execution","start":243,"end":322}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Direct arbitrary code execution from processing content","mappingType":"primary_impact","evidence":[{"from":"description","quote":"may lead to arbitrary code execution","start":286,"end":322}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[{"id":"SRC-c8f6f25e01bb52aca247","title":"Objective-See's Blog OSX.CDDS (OSX.MacMa)","publisher":"objective-see.org","url":"https://objective-see.org/blog/blog_0x69.html","date":null,"mentions":[{"quote":"A webkit “n-day” RCE (patched as CVE-2021-1789 in 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KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2022-05-04","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-7253","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":397},"priority":{"score":67.3,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 1846 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.31,"detail":"percentile 0.9655"},{"name":"Named in threat reports","points":3.87,"detail":"1 report"},{"name":"Public exploit code","points":0.0,"detail":"none found"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":6.16,"detail":"base score 8.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]},"lineage":{"familyId":"fam-class-apple-ios-macos-cwe-843"}}