Apple has recently patched a serious vulnerability targeting Mac users. Specifically, the vulnerability affected the macOS Big Sur upgrade that could lead to data loss with apparently no recovery.
macOS Big Sur Data Loss Bug
Reportedly, Mr. Macintosh shared details of a serious data loss vulnerability affecting macOS Big Sur. The glitch could leave the system virtually irrecoverable from the data loss, compelling the user to go for a reinstallation.
As elaborated in the post, the flaw appeared in the OS with Big Sur update 11.2. When prompted for the upgrade, the Big Sur 11.2 installer would start checking the system space for the upgrade. If the system lacks enough space, the installer would display an error to the user mentioning the space issue.
Ideally, the installer should have halted the upgrade process and have reverted to the previous macOS state.
However, because of the glitch, the installer would initiate the upgrade process thereby filling up empty space on the drive. After running out of space, the installer would restart and Mac would enter the “Boot Recovery Assistant”.
However, the user would eventually have to restart the device as the hard drive won’t appear in the startup disk menu. Once the system would shut down or restart, the installation process would begin again leading to a never-ending loop.
The bug would be more disastrous for the users having FileVault encryption enabled on their devices. It’s because the password required to enter the recovery mode won’t work.
Apple Patched The Flaw
The glitch typically affected the macOS Big Sur 11.2 installer, for which, Mr. Macintosh shared some workarounds.
Nonetheless, Apple has recently patched the bug with the release of macOS Big Sur 11.2.1 (20D75). The new installer now properly checks for space without any glitches.
macOS Big Sur 11.2.1 (20D75) full installer is now available for download.
I've confirmed the new installer now checks for free space properly.
— Mr. Macintosh (@ClassicII_MrMac) February 15, 2021
Hence, the users may not proceed safely to upgrade their devices with the latest Big Sur.
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