CVEvulnerability

CVE-2021-1871

9.8 CRITICAL Known exploited Published 2021-04-02 Modified 2026-06-17 Official page ↗

CISA Known Exploited Vulnerability

Apple iOS, iPadOS, and macOS WebKit Remote Code Execution Vulnerability — Apple iOS, iPadOS, and macOS

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.

Added to KEV
2021-11-03
Remediation due
2021-11-17
Ransomware use
Unknown
Required action
Apply updates per vendor instructions.
Notes
https://nvd.nist.gov/vuln/detail/CVE-2021-1871
Status
Analyzed
Published
2021-04-02
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)
9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0 ([email protected])
7.5 HIGH — AV:N/AC:L/Au:N/C:P/I:P/A:P

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..

Affected configurations

• apple ipados (< 14.4) • apple iphone os (< 14.4) • apple mac os x (>= 10.15 < 10.15.7) • apple mac os x 10.15.7 • apple macos (>= 11.0.1 < 11.2) • debian debian linux 10.0 • fedoraproject fedora 33

References