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PatchSiren cyber security CVE debrief

CVE-2021-30665 Apple CVE debrief

CVE-2021-30665 is an Apple WebKit memory corruption vulnerability affecting multiple Apple products. It was added to CISA’s Known Exploited Vulnerabilities catalog on 2021-11-03, which indicates known exploitation risk and makes timely patching a priority for organizations using Apple devices and WebKit-based software.

Vendor
Apple
Product
Multiple Products
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2021-11-03
Original CVE updated
2021-11-03
Advisory published
2021-11-03
Advisory updated
2021-11-03

Who should care

Apple device administrators, endpoint security teams, mobile device management operators, and users or teams responsible for Apple products that rely on WebKit should pay attention. Organizations with large fleets of Apple hardware or BYOD programs should treat this as a high-priority remediation item.

Technical summary

The public corpus identifies the issue as a WebKit memory corruption vulnerability in Apple Multiple Products. The source set does not provide exploit mechanics, affected version ranges, or a CVSS score, so the safest defensible summary is that the flaw affects Apple products using WebKit and was considered significant enough for inclusion in CISA’s KEV catalog.

Defensive priority

High. CISA placed CVE-2021-30665 in the KEV catalog on the same date as publication, with a remediation due date of 2021-11-17. KEV inclusion means defenders should prioritize updates over routine maintenance work.

Recommended defensive actions

  • Apply Apple security updates per vendor instructions as soon as possible.
  • Inventory Apple devices and applications that use WebKit to identify likely exposure.
  • Prioritize remediation ahead of the CISA due date of 2021-11-17.
  • Confirm endpoint management and patch compliance across Macs, iPhones, iPads, and other Apple-managed assets.
  • Monitor official Apple security advisories and CISA KEV updates for any follow-on guidance.

Evidence notes

CISA’s Known Exploited Vulnerabilities entry names the issue as "Apple Multiple Products WebKit Memory Corruption Vulnerability," marks it as a CVE item, lists Apple as the vendor project, and states the required action is to apply updates per vendor instructions. The KEV record shows dateAdded 2021-11-03 and dueDate 2021-11-17. The supplied corpus does not include a CVSS score or version-specific impact details.

Sources and references

Verified primary and authoritative sources

  • CVE-2021-30665 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2021-30665

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2021-30665 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2021-30665

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

  • CISA Known Exploited Vulnerabilities catalog

    Publisher, destination, and source semantics verified

    URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

    Cybersecurity and Infrastructure Security Agency - Official CISA catalog of vulnerabilities known to be exploited in the wild.

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

    cisa_kev

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.