CVE-2021-1870
Published 2021-04-02 · Updated 2026-06-17 · Source product-security@apple.com
Summary
CVE-2021-1870 is a critical-severity (CVSS 9.8) vulnerability in Apple iOS, iPadOS, and macOS. CISA added it to the Known Exploited Vulnerabilities catalog on November 3, 2021, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by November 17, 2021. CISA does not currently list it as used in ransomware campaigns. Apple has 96 vulnerabilities in the KEV catalog, 0 of them linked to ransomware.
All 96 known-exploited Apple vulnerabilities →Description
A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA Known-Exploited Vulnerability
Product: Apple — iOS, iPadOS, and macOS
Name: Apple iOS, iPadOS, and macOS WebKit Remote Code Execution Vulnerability
Date added: 2021-11-03 · Due: 2021-11-17
Required action: Apply updates per vendor instructions.
References
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN6ZOD62CTO54CHTMJTHVEF6R2Y532TJ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/
- https://security.gentoo.org/glsa/202104-03
- https://support.apple.com/en-us/HT212146
- https://support.apple.com/en-us/HT212147
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN6ZOD62CTO54CHTMJTHVEF6R2Y532TJ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/
- https://security.gentoo.org/glsa/202104-03