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CVE-2016-4661 Apple CVE debrief

CVE-2016-4661 affects macOS before 10.12.1. According to the NVD and Apple references, the issue is in the NTFS component, which misparses disk images. An attacker who can get a crafted app to be opened or processed on the affected system may be able to trigger a denial of service. The CVSS v3 vector indicates local access with user interaction required and impact limited to availability.

Vendor
Apple
Product
CVE-2016-4661
CVSS
MEDIUM 5.5
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

Mac administrators, endpoint security teams, and users running macOS versions earlier than 10.12.1 should pay attention, especially where untrusted apps or disk images may be encountered.

Technical summary

The vulnerability is categorized as CWE-20 (Improper Input Validation). NVD describes the flaw as an NTFS disk image parsing issue in macOS before 10.12.1, with a CVSS 3.0 vector of AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H. That combination suggests an attacker needs local conditions and user involvement, and the main effect is service availability loss rather than data theft or code execution.

Defensive priority

Medium. The issue is not scored as critical, but it can still disrupt affected systems and should be remediated by updating to a fixed macOS release.

Recommended defensive actions

  • Upgrade affected Macs to macOS 10.12.1 or later.
  • Avoid opening untrusted apps or disk images on vulnerable systems.
  • Use application and device controls to reduce exposure to unknown software.
  • Review Apple security updates and confirm affected endpoints are patched.

Evidence notes

The summary is based on the NVD record for CVE-2016-4661 and the Apple vendor advisory reference listed in NVD. The supplied source corpus indicates the affected product scope as macOS versions before 10.12.1 and identifies the NTFS component as the source of the parsing issue. No exploit details are included here.

Official resources

CVE published on 2017-02-20 and later modified on 2026-05-13. The supplied references show Apple as the vendor source and NVD as the official vulnerability database record; the advisory context points to a vendor-disclosed issue affecting a