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APPLE-SA-2021-04-26-2 macOS Big Sur 11.3

macOS Big Sur 11.3 addresses the following issues.
Information about the security content is also available at
https://support.apple.com/HT212325.

APFS
Available for: macOS Big Sur
Impact: A local attacker may be able to elevate their privileges
Description: A logic issue was addressed with improved state
management.
CVE-2021-1853: Gary Nield of ECSC Group plc and Tim
Michaud(@TimGMichaud) of Zoom Video Communications

AppleMobileFileIntegrity
Available for: macOS Big Sur
Impact: A malicious application may be able to bypass Privacy
preferences
Description: An issue in code signature validation was addressed with
improved checks.
CVE-2021-1849: Siguza

Apple Neural Engine
Available for: macOS Big Sur
Impact: A malicious application may be able to execute arbitrary code
with kernel privileges
Description: An out-of-bounds read was addressed with improved input
validation.
CVE-2021-1867: Zuozhi Fan (@pattern_F_) and Wish Wu(吴潍浠) of Ant Group
Tianqiong Security Lab

Archive Utility
Available for: macOS Big Sur
Impact: A malicious application may bypass Gatekeeper checks
Description: A logic issue was addressed with improved state
management.
CVE-2021-1810: an anonymous researcher

Audio
Available for: macOS Big Sur
Impact: An application may be able to read restricted memory
Description: A memory corruption issue was addressed with improved
validation.
CVE-2021-1808: JunDong Xie of Ant Security Light-Year Lab

CFNetwork
Available for: macOS Big Sur
Impact: Processing maliciously crafted web content may disclose
sensitive user information
Description: A memory initialization issue was addressed with
improved memory handling.
CVE-2021-1857: an anonymous researcher

CoreAudio
Available for: macOS Big Sur
Impact: Processing a maliciously crafted audio file may disclose
restricted memory
Description: An out-of-bounds read was addressed with improved input
validation.
CVE-2021-1846: JunDong Xie of Ant Security Light-Year Lab

CoreAudio
Available for: macOS Big Sur
Impact: A malicious application may be able to read restricted memory
Description: A memory corruption issue was addressed with improved
validation.
CVE-2021-1809: JunDong Xie of Ant Security Light-Year Lab

CoreFoundation
Available for: macOS Big Sur
Impact: A malicious application may be able to leak sensitive user
information
Description: A validation issue was addressed with improved logic.
CVE-2021-30659: Thijs Alkemade of Computest

CoreGraphics
Available for: macOS Big Sur
Impact: Opening a maliciously crafted file may lead to unexpected
application termination or arbitrary code execution
Description: A memory corruption issue was addressed with improved
validation.
CVE-2021-1847: Xuwei Liu of Purdue University

CoreText
Available for: macOS Big Sur
Impact: Processing a maliciously crafted font may result in the
disclosure of process memory
Description: A logic issue was addressed with improved state
management.
CVE-2021-1811: Xingwei Lin of Ant Security Light-Year Lab

curl
Available for: macOS Big Sur
Impact: An attacker may provide a fraudulent OCSP response that would
appear valid
Description: This issue was addressed with improved checks.
CVE-2020-8286: an anonymous researcher

curl
Available for: macOS Big Sur
Impact: A remote attacker may be able to cause a denial of service
Description: A buffer overflow was addressed with improved input
validation.
CVE-2020-8285: xnynx

DiskArbitration
Available for: macOS Big Sur
Impact: A malicious application may be able to modify protected parts
of the file system
Description: A permissions issue existed in DiskArbitration. This was
addressed with additional ownership checks.
CVE-2021-1784: Mikko Kenttälä (@Turmio_) of SensorFu, Csaba Fitzl
(@theevilbit) of Offensive Security, and an anonymous researcher

FaceTime
Available for: macOS Big Sur
Impact: Muting a CallKit call while ringing may not result in mute
being enabled
Description: A logic issue was addressed with improved state
management.
CVE-2021-1872: Siraj Zaneer of Facebook

FontParser
Available for: macOS Big Sur
Impact: Processing a maliciously crafted font file may lead to
arbitrary code execution
Description: An out-of-bounds read was addressed with improved input
validation.
CVE-2021-1881: an anonymous researcher, Xingwei Lin of Ant Security
Light-Year Lab, Mickey Jin of Trend Micro, and Hou JingYi
(@hjy79425575) of Qihoo 360

Foundation
Available for: macOS Big Sur
Impact: An application may be able to gain elevated privileges
Description: A memory corruption issue was addressed with improved
validation.
CVE-2021-1882: Gabe Kirkpatrick (@gabe_k)

Foundation
Available for: macOS Big Sur
Impact: A malicious application may be able to gain root privileges
Description: A validation issue was addressed with improved logic.
CVE-2021-1813: Cees Elzinga

Heimdal
Available for: macOS Big Sur
Impact: Processing maliciously crafted server messages may lead to
heap corruption
Description: This issue was addressed with improved checks.
CVE-2021-1883: Gabe Kirkpatrick (@gabe_k)

Heimdal
Available for: macOS Big Sur
Impact: A remote attacker may be able to cause a denial of service
Description: A race condition was addressed with improved locking.
CVE-2021-1884: Gabe Kirkpatrick (@gabe_k)

ImageIO
Available for: macOS Big Sur
Impact: Processing a maliciously crafted image may lead to arbitrary
code execution
Description: This issue was addressed with improved checks.
CVE-2021-1880: Xingwei Lin of Ant Security Light-Year Lab
CVE-2021-30653: Ye Zhang of Baidu Security
CVE-2021-1814: Ye Zhang of Baidu Security, Mickey Jin & Qi Sun of
Trend Micro, and  Xingwei Lin of Ant Security Light-Year Lab
CVE-2021-1843: Ye Zhang of Baidu Security

ImageIO
Available for: macOS Big Sur
Impact: Processing a maliciously crafted image may lead to arbitrary
code execution
Description: An out-of-bounds read was addressed with improved bounds
checking.
CVE-2021-1885: CFF of Topsec Alpha Team

ImageIO
Available for: macOS Big Sur
Impact: Processing a maliciously crafted image may lead to arbitrary
code execution
Description: An out-of-bounds write issue was addressed with improved
bounds checking.
CVE-2021-1858: Mickey Jin of Trend Micro

Installer
Available for: macOS Big Sur
Impact: A malicious application may bypass Gatekeeper checks
Description: This issue was addressed with improved handling of file
metadata.
CVE-2021-30658: Wojciech Reguła (@_r3ggi) of SecuRing

Intel Graphics Driver
Available for: macOS Big Sur
Impact: A malicious application may be able to execute arbitrary code
with kernel privileges
Description: An out-of-bounds write issue was addressed with improved
bounds checking.
CVE-2021-1841: Jack Dates of RET2 Systems, Inc.
CVE-2021-1834: ABC Research s.r.o. working with Trend Micro Zero Day
Initiative

Kernel
Available for: macOS Big Sur
Impact: A malicious application may be able to disclose kernel memory
Description: A memory initialization issue was addressed with
improved memory handling.
CVE-2021-1860: @0xalsr

Kernel
Available for: macOS Big Sur
Impact: A local attacker may be able to elevate their privileges
Description: A memory corruption issue was addressed with improved
validation.
CVE-2021-1840: Zuozhi Fan (@pattern_F_) of Ant Group Tianqiong
Security Lab

Kernel
Available for: macOS Big Sur
Impact: An application may be able to execute arbitrary code with
kernel privileges
Description: A logic issue was addressed with improved state
management.
CVE-2021-1851: @0xalsr

Kernel
Available for: macOS Big Sur
Impact: Copied files may not have the expected file permissions
Description: The issue was addressed with improved permissions logic.
CVE-2021-1832: an anonymous researcher

Kernel
Available for: macOS Big Sur
Impact: A malicious application may be able to disclose kernel memory
Description: An out-of-bounds read was addressed with improved bounds
checking.
CVE-2021-30660: Alex Plaskett

libxpc
Available for: macOS Big Sur
Impact: A malicious application may be able to gain root privileges
Description: A race condition was addressed with additional
validation.
CVE-2021-30652: James Hutchins

libxslt
Available for: macOS Big Sur
Impact: Processing a maliciously crafted file may lead to heap
corruption
Description: A double free issue was addressed with improved memory
management.
CVE-2021-1875: Found by OSS-Fuzz

Login Window
Available for: macOS Big Sur
Impact: A malicious application with root privileges may be able to
access private information
Description: This issue was addressed with improved entitlements.
CVE-2021-1824: Wojciech Reguła (@_r3ggi) of SecuRing

Notes
Available for: macOS Big Sur
Impact: Locked Notes content may have been unexpectedly unlocked
Description: A logic issue was addressed with improved state
management.
CVE-2021-1859: Syed Ali Shuja (@SyedAliShuja) of Colour King Pvt. Ltd

NSRemoteView
Available for: macOS Big Sur
Impact: Processing maliciously crafted web content may lead to
arbitrary code execution
Description: A use after free issue was addressed with improved
memory management.
CVE-2021-1876: Matthew Denton of Google Chrome

Preferences
Available for: macOS Big Sur
Impact: A local user may be able to modify protected parts of the
file system
Description: A parsing issue in the handling of directory paths was
addressed with improved path validation.
CVE-2021-1815: Zhipeng Huo (@R3dF09) and Yuebin Sun (@yuebinsun2020)
of Tencent Security Xuanwu Lab (xlab.tencent.com)
CVE-2021-1739: Zhipeng Huo (@R3dF09) and Yuebin Sun (@yuebinsun2020)
of Tencent Security Xuanwu Lab (xlab.tencent.com)
CVE-2021-1740: Zhipeng Huo (@R3dF09) and Yuebin Sun (@yuebinsun2020)
of Tencent Security Xuanwu Lab (xlab.tencent.com)

Safari
Available for: macOS Big Sur
Impact: A malicious website may be able to track users by setting
state in a cache
Description: An issue existed in determining cache occupancy. The
issue was addressed through improved logic.
CVE-2021-1861: Konstantinos Solomos of University of Illinois at
Chicago

Safari
Available for: macOS Big Sur
Impact: A malicious website may be able to force unnecessary network
connections to fetch its favicon
Description: A logic issue was addressed with improved state
management.
CVE-2021-1855: Håvard Mikkelsen Ottestad of HASMAC AS

SampleAnalysis
Available for: macOS Big Sur
Impact: A local attacker may be able to elevate their privileges
Description: A logic issue was addressed with improved state
management.
CVE-2021-1868: Tim Michaud of Zoom Communications

smbx
Available for: macOS Big Sur
Impact: An attacker in a privileged network position may be able to
leak sensitive user information
Description: An integer overflow was addressed with improved input
validation.
CVE-2021-1878: Aleksandar Nikolic of Cisco Talos
(talosintelligence.com)

System Preferences
Available for: macOS Big Sur
Impact: A malicious application may bypass Gatekeeper checks
Description: A logic issue was addressed with improved state
management.
CVE-2021-30657: an anonymous researcher

tcpdump
Available for: macOS Big Sur
Impact: A remote attacker may be able to cause a denial of service
Description: This issue was addressed with improved checks.
CVE-2020-8037: an anonymous researcher

Time Machine
Available for: macOS Big Sur
Impact: A local attacker may be able to elevate their privileges
Description: The issue was addressed with improved permissions logic.
CVE-2021-1839: Tim Michaud(@TimGMichaud) of Zoom Video Communications
and Gary Nield of ECSC Group plc

WebKit
Available for: macOS Big Sur
Impact: Processing maliciously crafted web content may lead to a
cross site scripting attack
Description: An input validation issue was addressed with improved
input validation.
CVE-2021-1825: Alex Camboe of Aon’s Cyber Solutions

WebKit
Available for: macOS Big Sur
Impact: Processing maliciously crafted web content may lead to
arbitrary code execution
Description: A memory corruption issue was addressed with improved
state management.
CVE-2021-1817: an anonymous researcher

WebKit
Available for: macOS Big Sur
Impact: Processing maliciously crafted web content may lead to
universal cross site scripting
Description: A logic issue was addressed with improved restrictions.
CVE-2021-1826: an anonymous researcher

WebKit
Available for: macOS Big Sur
Impact: Processing maliciously crafted web content may result in the
disclosure of process memory
Description: A memory initialization issue was addressed with
improved memory handling.
CVE-2021-1820: an anonymous researcher

WebKit Storage
Available for: macOS Big Sur
Impact: Processing maliciously crafted web content may lead to
arbitrary code execution. Apple is aware of a report that this issue
may have been actively exploited.
Description: A use after free issue was addressed with improved
memory management.
CVE-2021-30661: yangkang(@dnpushme) of 360 ATA

WebRTC
Available for: macOS Big Sur
Impact: A remote attacker may be able to cause unexpected system
termination or corrupt kernel memory
Description: A use after free issue was addressed with improved
memory management.
CVE-2020-7463: Megan2013678

Wi-Fi
Available for: macOS Big Sur
Impact: An application may be able to cause unexpected system
termination or write kernel memory
Description: A memory corruption issue was addressed with improved
validation.
CVE-2021-1828: Zuozhi Fan (@pattern_F_) of Ant Group Tianqiong
Security Lab

Wi-Fi
Available for: macOS Big Sur
Impact: An application may be able to execute arbitrary code with
kernel privileges
Description: A type confusion issue was addressed with improved state
handling.
CVE-2021-1829: Tielei Wang of Pangu Lab

Wi-Fi
Available for: macOS Big Sur
Impact: An application may be able to execute arbitrary code with
system privileges
Description: The issue was addressed with improved permissions logic.
CVE-2021-30655: Gary Nield of ECSC Group plc and Tim
Michaud(@TimGMichaud) of Zoom Video Communications and Wojciech
Reguła (@_r3ggi) of SecuRing

Windows Server
Available for: macOS Big Sur
Impact: A malicious application may be able to unexpectedly leak a
user's credentials from secure text fields
Description: An API issue in Accessibility TCC permissions was
addressed with improved state management.
CVE-2021-1873: an anonymous researcher

Installation note:

This update may be obtained from the Mac App Store or
Apple's Software Downloads web site:
https://support.apple.com/downloads/

Information will also be posted to the Apple Security Updates
web site: https://support.apple.com/kb/HT201222

This message is signed with Apple's Product Security PGP key,
and details are available at:
https://www.apple.com/support/security/pgp/

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