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PatchSiren cyber security CVE debrief

CVE-2016-7621 Apple CVE debrief

CVE-2016-7621 is a kernel use-after-free issue in older Apple operating-system releases. According to the CVE description, it can let a local user execute arbitrary code in a privileged context or trigger a denial of service. The record is rated High severity, and the supplied data does not show a Known Exploited Vulnerabilities listing.

Vendor
Apple
Product
Unknown
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2017-02-20
Original CVE updated
2026-05-13
Advisory published
2017-02-20
Advisory updated
2026-05-13

Who should care

Apple device owners and administrators, especially teams managing iOS, macOS, and watchOS fleets through MDM or similar tooling. It matters most where local access is shared, lightly controlled, or available to untrusted users.

Technical summary

The issue is described as a kernel use-after-free (CWE-416). NVD assigns a CVSS v3.0 vector of AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, reflecting a local attack requiring low privileges but with potential for full compromise impact. The CVE description says affected versions are iOS before 10.2, macOS before 10.12.2, and watchOS before 3.1.3.

Defensive priority

High for affected endpoints because this is a kernel vulnerability with privilege-escalation potential. Prioritize any device that still runs the affected Apple OS versions, especially systems that permit local logins or run untrusted user workloads.

Recommended defensive actions

  • Update iOS to 10.2 or later, macOS to 10.12.2 or later, and watchOS to 3.1.3 or later, per the CVE description.
  • Inventory Apple devices to confirm no systems remain on affected releases.
  • Prioritize remediation for shared, kiosk, lab, or developer devices where local access is more likely.
  • Treat unexplained kernel crashes or instability on unpatched systems as a reason to expedite patch validation and deployment.
  • Use MDM or fleet-management controls to verify remediation status and prevent drift back to vulnerable versions.

Evidence notes

The supplied corpus states this is a kernel component issue in Apple products and identifies it as a use-after-free. The CVE description explicitly says it may allow local arbitrary code execution in a privileged context or cause denial of service. NVD also lists CWE-416 and the CVSS vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Note: the narrative summary in the CVE description and the NVD CPE version ranges are not perfectly aligned, so the descriptive version boundaries from the CVE text were used for remediation guidance.

Sources and references

Verified primary and authoritative sources

  • CVE-2016-7621 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2016-7621

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

  • CVE-2016-7621 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2016-7621

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

Supplemental references

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.