CVE-2021-30666

Timeline

Detection, updates, and resolution for this record.

1. Sep 8, 2021 · Catalog

   Detected

   Apple iOS WebKit contains a buffer-overflow 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 WebKit contains a buffer-overflow 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.

Affected

• cpe apple/iphone osversion unspecified
• vendor Apple iOSversion unspecified

Sources

• CISA KEVCVE-2021-30666

  Apple iOS WebKit contains a buffer-overflow 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-2021-30666

  Official CVE identifier

  cve.org
• FIRST EPSSCVE-2021-30666

  30-day exploitation probability 3.0%

  first.org
• NIST NVDCVE-2021-30666

  A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 12.5.3. 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..

  nvd.nist.gov

References

• CISA note · nvd.nist.gov
• Release Notes · support.apple.com
• Third Party Advisory · cisa.gov