The three updates make changes to iOS, macOS, and Safari but in each case, the stated goal is protecting Safari and the underlying browser engine against attacks exploiting the recently published Spectre vulnerability.
Meltdown-specific patches have already released for iOS (11.2), macOS (10.13.2), and tvOS (11.2). Browsers have been a particular focus for patching.
Apple said in a statement on Thursday. “Since exploiting many of these issues requires a malicious app to be loaded on your Mac or iOS device, we recommend downloading software only from trusted sources such as the App Store.”