Findings

CVE-2021-30661

Apple Multiple Products WebKit Storage Use-After-Free Vulnerability

Published Sep 8, 2021 · updated Jun 16, 2026 · apple safari

Apple iOS, iPadOS, macOS, tvOS, watchOS, and Safari WebKit Storage contain a use-after-free 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.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 8, 2021 · Catalog

    Detected

    Apple iOS, iPadOS, macOS, tvOS, watchOS, and Safari WebKit Storage contain a use-after-free 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.

  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

    Apple iOS, iPadOS, macOS, tvOS, watchOS, and Safari WebKit Storage contain a use-after-free 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.

Required action

Apply updates per vendor instructions.

CISA due date Nov 17, 2021

Affected

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

Sources

  • CISA KEVCVE-2021-30661

    Apple iOS, iPadOS, macOS, tvOS, watchOS, and Safari WebKit Storage contain a use-after-free 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.orgCVE-2021-30661

    Official CVE identifier

    cve.org
  • FIRST EPSSCVE-2021-30661

    30-day exploitation probability 4.5%

    first.org
  • NIST NVDCVE-2021-30661

    A use after free issue was addressed with improved memory management. This issue is fixed in Safari 14.1, iOS 12.5.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5, macOS Big Sur 11.3. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aw

    nvd.nist.gov

References

CVE-2021-30661 · ZeroDay Findings