Is CVE-2021-30663 actively exploited?

CVE-2021-30663 has no public evidence of in-the-wild exploitation as of 2025-10-23.

What is the CVSS score for CVE-2021-30663?

CVE-2021-30663 has a CVSS score of 8.8 (HIGH severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

How do I patch CVE-2021-30663?

Patch guidance is available from apple security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2021-30663.

Fix CVE-2021-30663 - HIGH apple safari

Q: Which products are affected by CVE-2021-30663?

6 products: apple safari, apple ipados, apple iphone os, apple iphone os, apple macos, and 1 more.

Description

An integer overflow was addressed with improved input validation. This issue is fixed in iOS 14.5.1 and iPadOS 14.5.1, tvOS 14.6, iOS 12.5.3, Safari 14.1.1, macOS Big Sur 11.3.1. Processing maliciously crafted web content may lead to arbitrary code execution.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack Vector: network
Complexity: low
Privileges: none
User Action: required
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Weaknesses: CWE-190 · Integer Overflow CWE-190 · Integer Overflow

Metadata

Primary Vendor: APPLE
Published: 9/8/2021
Last Modified: 10/23/2025
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

apple : safariapple : ipadosapple : iphone_osapple : iphone_osapple : macosapple : tvos

Remediation Guidance

Executive Summary

View on NIST NVD