CVE-2021-30665VulnerabilityPublished 11/03/2021Updated 10/24/2026

CVE-2021-30665: Apple Multiple Products WebKit Memory Corruption Vulnerability

Affects Apple Multiple ProductsSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 11/03/2021
KEV deadline: 11/17/2021
EPSS: 3.7% chance of exploitation in 30 days – higher than 89% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2021-30665 (opens in a new tab)

Description

A memory corruption vulnerability exists in WebKit used by multiple Apple products including iOS, iPadOS, macOS, watchOS, and tvOS. This flaw can lead to code execution when processing maliciously crafted web content. The vulnerability affects HTML parsers relying on WebKit, including Apple Safari and other products using WebKit. Exploitation in the wild has been observed. No specific affected versions or patch details are provided in the input data.

Summary

CVE-2021-30665 is a memory corruption vulnerability in the WebKit engine used by various Apple operating systems and products. The flaw allows remote attackers to execute arbitrary code by delivering specially crafted web content that triggers memory corruption during HTML parsing. This vulnerability impacts Apple Safari and potentially other applications using WebKit for HTML processing. Exploits have been observed in the wild, indicating active targeting. No explicit patch or remediation information is included in the provided data.

Impact

Successful exploitation can lead to arbitrary code execution on affected devices running Apple iOS, iPadOS, macOS, watchOS, and tvOS. This could allow attackers to take control of the affected system or execute malicious payloads remotely via crafted web content. The presence of known exploits in the wild increases the urgency and risk to users of vulnerable products.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Users and administrators should monitor official Apple security advisories for updates and apply any available patches promptly once released. Until then, cautious browsing and avoiding untrusted web content may reduce exposure.

Weaknesses

CWE-787Out-of-bounds Write (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 09:40:53 UTC

Weaknesses

References

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