CVE-2021-30661VulnerabilityPublished 11/03/2021Updated 10/24/2026

CVE-2021-30661: Apple Multiple Products WebKit Storage Use-After-Free 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: 4.5% chance of exploitation in 30 days – higher than 91% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2021-30661 (opens in a new tab)

Description

CVE-2021-30661 is a use-after-free vulnerability in WebKit Storage affecting multiple Apple products including iOS, iPadOS, macOS, tvOS, watchOS, and Safari. The flaw allows code execution when processing maliciously crafted web content. It also potentially affects other products using WebKit for HTML parsing. Exploitation in the wild has been observed. No explicit patch information is provided in the input data.

Summary

This vulnerability involves a use-after-free condition in the WebKit Storage component used by Apple operating systems and Safari browser. When malicious web content is processed, this flaw can lead to arbitrary code execution. The issue also extends to other software relying on WebKit for HTML parsing. The vulnerability is tracked as CVE-2021-30661 and has been exploited in the wild, indicating active threat usage.

Impact

Successful exploitation can lead to arbitrary code execution on affected devices, potentially allowing attackers to execute malicious code in the context of the user. This impacts confidentiality, integrity, and availability of the affected systems. The vulnerability affects multiple Apple platforms and Safari, as well as other products using WebKit for HTML processing.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no patch or official fix information is provided, users and administrators should monitor Apple security advisories for updates and apply patches promptly once available.

Weaknesses

CWE-416Use After Free (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 09:41:03 UTC

Weaknesses

References

Related threats