The exact nature of the security issue which is labelled as the CVE-2021-1844 was not revealed by Apple although it has been described as a memory corruption issue that could provide space for a malicious website to run unauthorised codes. Its discovery was credited to Clément Lecigne from Google’s Threat Analysis Group and Alison Huffman of the Microsoft Browser Vulnerability Research team.
For iPhone and iPod Touch, the patch comes in the form of iOS 14.4.1 and similarly, iPad users can also obtain it via iPadOS 14.4.1. On another hand, the fix is being delivered to Apple Watch Series 3 and above through watchOS 7.3.2.
Mac users should keep a look for macOS Big Sur 11.2.3 for the security fix but if they are using an older version of the operating system such as Catalina and Mojave, the update is delivered directly to the Safari web browser. Once the update is applied, the build number of the Safari 14.0.3 on their Catalina machine will be refreshed to 15610.4.3.1.7 while those on Mojave will see build 14610.4.3.1.7.