Apple outs iOS 11.2.2 for iPhone, iPad and iPod touch to fix the Spectre vulnerability that came to light earlier this month.
Take note that the Spectre vulnerability is being mitigated, not fixed, because it’s a problem with modern CPU architecture and cannot be resolved by a software update. It’s more of a hardware-based exploit that takes advantage of the processor’s speculative execution mechanism, potentially allowing hackers to gain access to sensitive information.
Nevertheless, Apple says it recommends the update for all users. To download the update, go to Settings > General > Software Update. The update is only about 75MB.