CVE-2021-30666

HIGH8.8

CISA KEV

Published 2021-09-08 · Updated 2026-06-17 · Source product-security@apple.com

Summary

CVE-2021-30666 is a high-severity (CVSS 8.8) vulnerability in Apple iOS. 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 buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 12.5.3. Processing maliciously crafted web content may lead to 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:R/S:U/C:H/I:H/A:H

CWE-119CWE-119

CISA Known-Exploited Vulnerability

Product: Apple — iOS

Name: Apple iOS WebKit Buffer Overflow Vulnerability

Date added: 2021-11-03 · Due: 2021-11-17

Required action: Apply updates per vendor instructions.

References

View on NVD

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