A Vulnerability in macOS Big Sur, iOS and iPadOS Could Allow for Arbitrary Code Execution

DESCRIPTION:
A vulnerability has been discovered in macOS Big Sur, iOS and iPadOS,
which could allow for arbitrary code execution.

* iOS is a mobile operating system for mobile devices, including the
iPhone, iPad, and iPod touch.
* iPadOS is the successor to iOS 12 and is a mobile operating system for
iPads.
* macOS Big Sur is the 17th and current major release of macOS.

Successful exploitation of this vulnerability could allow an attacker to
execute arbitrary code with kernel privileges to take full control over
a device.

IMPACT:
A vulnerability has been discovered in macOS Big Sur, iOS and iPadOS
that could allow for arbitrary code execution. This vulnerability occurs
due to a memory corruption issue in IOMobileFrameBuffer that was
addressed with improved memory handling. Successful exploitation of this
vulnerability could result in arbitrary code execution with kernel
privileges to take full control over a device.

SYSTEM AFFECTED:
* iOS prior to version 14.7.1
* iPadOS prior to version 14.7.1
* macOS Big Sur prior to version 11.5.1

RECOMMENDATIONS:
We recommend the following actions be taken:

* Apply appropriate patches provided by Apple to vulnerable systems
immediately after appropriate testing.
* Run all software as a nonprivileged user (one without administrative
privileges) to diminish the effects of a successful attack.
* Remind users not to download, accept or execute files from untrusted
and unknown sources.
* Remind users not to visit untrusted websites or follow links provided
by untrusted or unknown sources.
* Evaluate read, write, and execute permissions on all newly installed
software.
* Apply the Principle of Least Privilege to all systems and services.

REFERENCES:
https://support.apple.com/en-us/HT212622
https://support.apple.com/en-us/HT212623
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-30807