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Findings

CVE-2021-30665

Apple Multiple Products WebKit Memory Corruption Vulnerability

Published Sep 8, 2021 · corrected/updated Jun 16, 2026 · apple ipados · evidence confidence very high

A memory corruption issue was addressed with improved state management. This issue is fixed in watchOS 7.4.1, iOS 14.5.1 and iPadOS 14.5.1, tvOS 14.6, iOS 12.5.3, macOS Big Sur 11.3.1. 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..

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2021-30665 is a high public vulnerability record for apple ipados. CISA lists it as known exploited. Published remediation guidance: Apply updates per vendor instructions. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether apple ipados is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: apple/ipados; apple/iphone os; apple/macos; apple/tvos. Published remediation guidance: Apply updates per vendor instructions. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 8.8, EPSS 3.7%. CISA lists it as known exploited. Weakness classes: CWE-787. Sources contributing to this record: cisa_kev, cve_org, epss, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Confirmed in CISA KEV since Nov 3, 2021. Listed in the CISA Known Exploited Vulnerabilities catalog.

  • Patch and remediation

    Apply updates per vendor instructions. CISA due date Nov 17, 2021.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 8, 2021 · Catalog

    Detected

    A memory corruption issue was addressed with improved state management. This issue is fixed in watchOS 7.4.1, iOS 14.5.1 and iPadOS 14.5.1, tvOS 14.6, iOS 12.5.3, macOS Big Sur 11.3.1. 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..

  2. Nov 3, 2021 · CISA KEV

    Known exploited

    Apply updates per vendor instructions.

  3. Nov 17, 2021 · CISA KEV

    Remediation due

    Apply updates per vendor instructions.

  4. Jun 16, 2026 · Catalog

    Updated

    A memory corruption issue was addressed with improved state management. This issue is fixed in watchOS 7.4.1, iOS 14.5.1 and iPadOS 14.5.1, tvOS 14.6, iOS 12.5.3, macOS Big Sur 11.3.1. 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..

Affected

  • cpe apple/ipadosversion unspecified
  • cpe apple/iphone osversion unspecified
  • cpe apple/macosversion unspecified
  • cpe apple/tvosversion unspecified
  • cpe apple/watchosversion unspecified
  • vendor Apple Multiple Productsversion unspecified

Sources

  • CISA KEVConfirmed exploitationCVE-2021-30665

    Apple iOS, iPadOS, macOS, watchOS, and tvOS WebKit contain a memory corruption vulnerability that leads to code execution when processing maliciously crafted web content. 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.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2021-30665

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-30665

    30-day exploitation probability 3.7%

    first.org
  • NIST NVDVulnerability recordCVE-2021-30665

    A memory corruption issue was addressed with improved state management. This issue is fixed in watchOS 7.4.1, iOS 14.5.1 and iPadOS 14.5.1, tvOS 14.6, iOS 12.5.3, macOS Big Sur 11.3.1. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware

    nvd.nist.gov

References