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CVE-2021-1870: Apple iOS, iPadOS, and macOS WebKit Remote Code Execution Vulnerability
Apple iOS, iPadOS, and macOS · in CISA KEV since 2021-11-03
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2021-11-03added to KEV
2021-11-17federal remediation due date
7.71%EPSS exploit probability (30 days) 94.4th percentile
9.8 CRITICALCVSS 3.1
Unknownknown ransomware use
215days from NVD publication to KEV
What it is
Apple iOS, iPadOS, and macOS WebKit contain an unspecified logic vulnerability that allows a remote attacker to execute code. 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.
Required action (CISA)
Apply updates per vendor instructions.
| CWE | CWE-1173 |
|---|---|
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD published | 2021-04-02 (Analyzed) |
Original records: NVD · CISA KEV · JSON: /api/cve/CVE-2021-1870.json · all KEV CVEs
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Get the full file: Exploited Vulnerabilities Brief – September 2026 ($29): this month's KEV additions ranked by EPSS, ransomware use and due date, ready to hand to a patch team. Checkout by Polar.
Get the full file: Exploited Vulnerabilities Brief – September 2026 ($29): this month's KEV additions ranked by EPSS, ransomware use and due date, ready to hand to a patch team. Checkout by Polar.