Apart from iOS 14.5.1, Apple recently released an update to iOS 12.5.3 for older iPhone models that are not eligible for newer iOS to address security vulnerabilities associated with WebKit.
According to Makeusesoft, iOS 12.5.3 fixes a total of four WebKit-related vulnerabilities. The “buffer overflow” issue allows strangers to collect malicious web content which, if processed by iOS, could result in arbitrary code execution. If security and privacy are important to users, they definitely don’t want their devices to run code that malicious people could insert into web content.
Three of these vulnerabilities were found in the WebKit engine, while the fourth involved the WebKit hosting system. iOS 12.5.3 applies this update to compatible devices including iPhone 5s / 6/6 Plus, iPad Air / Mini 2 / Mini 3, and iPod touch 6th generation.
with iOS 14.5.1, Apple claims to have received reports of security vulnerabilities being actively exploited in real life. Hence, it is recommended that users update it immediately.
To update compatible iPhone, iPad or iPod touch to iOS 12.5.3, users can use Apple’s OTA update mechanism by going to Settings> General> Software Update. If you see a message there confirming new software updates are available, choose to install them immediately over the network.