Apple first patched the Meltdown flaw (CVE-2017-5753) on December 6, 2017, with the release of iOS 11.2, macOS 10.13.2, and tvOS 11.2.
The company then patched the Spectre flaws (CVE-2017-5753 and CVE-2017-5715) in a separate security update released on January 8, 2018, for macOS High Sierra 10.13.2, iOS 11.2.2, and Safari 11.0.2.
Yesterday, Apple's security team released supplemental security updates for older macOS versions —macOS Sierra 10.12.6 and OS X El Capitan 10.11.6.
These updates backported the company's Meltdown patch, originally released in December 2017.
Many users have criticized Apple for releasing Meltdown and Spectre patches only for recent OS versions. The criticism came from the fact that users had to update the entire OS to receive a critical security fix. In some cases, updating the OS was not an option, meaning many users were left running an insecure OS.
While Apple's security team is mum on such issues, many experts now expect the company to backport the Spectre flaw to older macOS versions in a future update as well, and maybe backport the patches for older iOS versions too.
Besides the backported Meltdown patches, the macOS security updates also include a fix for a zero-day released at the end of last year by a security researcher known as S1guza.
Apple also released security fixes for other products as well. Please refer to the table below for more details.
Name and information link
Available for
Number of vulnerabilities
Release date
| iTunes 12.7.3 for Windows | Windows 7 and later | 2 | 23 Jan 2018 |
| iCloud for Windows 7.3 | Windows 7 and later | 2 | 23 Jan 2018 |
| Safari 11.0.3 | OS X El Capitan 10.11.6, macOS Sierra 10.12.6, and macOS High Sierra 10.13.3 | 3 | 23 Jan 2018 |
| watchOS 4.2.2 | All Apple Watch models | 12 | 23 Jan 2018 |
| iOS 11.2.5 | iPhone 5s and later, iPad Air and later, and iPod touch 6th generation | 13 | 23 Jan 2018 |
| macOS High Sierra 10.13.3, Security Update 2018-001 Sierra, and Security Update 2018-001 El Capitan | macOS High Sierra 10.13.2, macOS Sierra 10.12.6, and OS X El Capitan 10.11.6 | 17 | 23 Jan 2018 |
| tvOS 11.2.5 | Apple TV 4K and Apple TV (4th generation) | 12 | 23 Jan 2018 |
| Source |