Release record
Release notes
Editorial synthesis with inline references and a source ledger when citations are available.
Source ledger
Sources are linked to the claims they support. Publication and access dates are shown when available.
Apple Support · Apple · 2023-11-03T00:00:00.000Z · iOS 11.2.1 — Released December 13, 2017
Apple Support · Apple · 2023-11-03T00:00:00.000Z · iOS 11.2.1 — security content
Documented & observed
Source-linked features, fixes, known issues, removals, and community-observed behavior recorded across this version’s appearances and verified builds.
Release changes
Features, fixes, removals, and regressions first observed in this release record.
security · fixed
Apple’s consumer and security notes jointly describe the Home-focused functional repair and the CVE-tracked validation change.
Recorded at Public
Milestones
Every recorded channel appearance in chronological order. Open an appearance for any available build, scope, notes, and sources.
Public release
iOS 11.2.1 reached the public release channel on December 13, 2017. iOS 11.2.1 reached the public channel on December 13, 2017. The narrowly scoped update repaired shared-user remote access in Home and included a documented HomeKit security correction. This article records the public appearance only and does not assign cumulative notes to an earlier beta.
Historical context
Pace, intervals, and duration compared with earlier releases on the same platform.
Historical avg for .2.1 releases
68 days, 6.0 milestones
Based on 1 previous iOS .2.1 releases
| Version | Year | Cycle | Milestones | Avg. Interval |
|---|---|---|---|---|
| iOS 4.2.1 | 2010 | 68d | 6 | 14d |
Scroll horizontally to compare every historical field.