According to the release notes, the update fixes a security flaw that could have been exploited by hackers. Explaining its impact, Apple said, “Processing web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.
In general, users are advised to keep their iPhones updated to the latest OS version. However, when it comes to Rapid Security Response updates, users should update their devices immediately as hackers and bad actors can access their personal data.
What is Rapid Security Response?
According to Apple’s support page, Rapid Security Response (RSR) is a mechanism for applying security fixes to users more frequently without requiring full software updates. These responses are included in any upcoming minor updates (not upgrades) and, on the Mac, applicable content appears on the preboot volume (via symbolic links in /system/cryptex/).
Rapid security responses that involve the operating system require a device restart. These updates are available for iPad, iPhone and Mac. For example, in macOS, applicable operating system content may be made available to Safari and its associated processes only with a relaunch of those processes, however, to make this content broadly available to the rest of the operating system restart is required.
“Rapid security responses also do not follow managed software update delays; However, because they only apply to the latest minor operating system version, if that minor operating system update is delayed, the response is effectively delayed as well. If necessary, the user can also delete the responses,” notes Apple on the support page.