According to tech media outlet iDownloadBlog, Apple has officially closed the verification channel for iOS 18.3.

This action implies that users who have upgraded to iOS 18.3.1 can only proceed to newer versions and cannot revert to iOS 18.3 or any previous iterations.

iOS 18.3 was officially launched on January 28th of this year. Apple customarily ceases signing older iOS versions within a week or two of a new release.

However, a critical vulnerability that jeopardized user data security was discovered in the previous iOS 18.3 version. Consequently, many iPhone users perceived the timing of the closure announcement as deliberate.

Image source: Internet

So, what exactly did iOS 18.3 update, and why did a critical vulnerability surface?

iOS 18.3 primarily focused on security patches and feature enhancements, addressing a total of 29 security vulnerabilities. These included issues related to AirPlay, unexpected app crashes, arbitrary code execution, and more.

Apart from security fixes, iOS 18.3 also introduced several feature improvements. For instance, it addressed battery life concerns, enhanced signal reception in underground garages, improved system smoothness, and resolved overheating issues caused by excessive daily mobile app usage.

Notably, iOS 18.3 added the capability to capture poster flyers by long-pressing the camera control button on iPhone 16 series devices and allowed direct addition of calendar events. Visually, it introduced new wallpapers and refined the dark mode transition for home screen icons for a more cohesive look.

Image source: Apple

Nevertheless, this version also harbored issues, particularly the critical vulnerability mentioned earlier.

"The vulnerability could enable hackers to disable USB Restricted Mode while the device is locked, bypassing security mechanisms and gaining unauthorized access. If exploited, users' personal information would be highly susceptible to leakage, posing significant security risks. It was later confirmed that this vulnerability was used in targeted attacks against specific users."

Thus, on February 11th, Apple released iOS 18.3.1, primarily to address the lingering USB vulnerability.

The decision to cease signing iOS 18.3 is partly motivated by safeguarding everyone's system security and aligns with Apple's standard practice of stopping the signing of older versions.

Image source: Apple

For iPhone users who have already upgraded to iOS 18.3.1, there are also advantages to the new version.

Besides continuing to refine the basic features of iOS 18.3, it offers smoother feature optimization. Notably, it has improved the speed of camera startup, focusing, and 3D facial unlock.

Most importantly, it fixes a severe security vulnerability related to accessibility features, effectively thwarting hackers from attacking and gaining unauthorized access to devices. This not only bolsters device security but also better safeguards users' personal information.

Image source: Apple's official website

In conclusion, consider carefully before upgrading to iOS 18.3.1, as you may find yourself unable to downgrade thereafter!

Source: Lei Technology