About the security content of watchOS 5.1

This document describes the security content of watchOS 5.1.

About Apple security updates

For our customers' protection, Apple doesn't disclose, discuss, or confirm security issues until an investigation has occurred and patches or releases are available. Recent releases are listed on the Apple security updates page.

For more information about security, see the Apple Product Security page. You can encrypt communications with Apple using the Apple Product Security PGP Key.

Apple security documents reference vulnerabilities by CVE-ID when possible.

watchOS 5.1

AppleAVD

Available for: Apple Watch Series 1 and later

Impact: A malicious application may be able to elevate privileges

Description: A memory corruption issue was addressed with improved input validation.

CVE-2018-4384: Natalie Silvanovich of Google Project Zero

CoreCrypto

Available for: Apple Watch Series 1 and later

Impact: An attacker may be able to exploit a weakness in the Miller-Rabin primality test to incorrectly identify prime numbers

Description: An issue existed in the method for determining prime numbers. This issue was addressed by using pseudorandom bases for testing of primes.

CVE-2018-4398: Martin Albrecht, Jake Massimo and Kenny Paterson of Royal Holloway, University of London, and Juraj Somorovsky of Ruhr University, Bochum

ICU

Available for: Apple Watch Series 1 and later

Impact: Processing a maliciously crafted string may lead to heap corruption

Description: A memory corruption issue was addressed with improved input validation.

CVE-2018-4394: Erik Verbruggen of The Qt Company

IPSec

Available for: Apple Watch Series 1 and later

Impact: An application may be able to gain elevated privileges

Description: An out-of-bounds read was addressed with improved input validation.

CVE-2018-4371: Tim Michaud (@TimGMichaud) of Leviathan Security Group

Kernel

Available for: Apple Watch Series 1 and later

Impact: An application may be able to execute arbitrary code with kernel privileges

Description: A memory corruption issue was addressed by removing the vulnerable code.

CVE-2018-4420: Mohamed Ghannam (@_simo36)

Kernel

Available for: Apple Watch Series 1 and later

Impact: An application may be able to read restricted memory

Description: A memory initialization issue was addressed with improved memory handling.

CVE-2018-4413: Juwei Lin (@panicaII) of TrendMicro Mobile Security Team

Kernel

Available for: Apple Watch Series 1 and later

Impact: An application may be able to execute arbitrary code with kernel privileges

Description: A memory corruption issue was addressed with improved memory handling.

CVE-2018-4419: Mohamed Ghannam (@_simo36)

Mail

Available for: Apple Watch Series 1 and later

Impact: Processing a maliciously crafted message may lead to a denial of service

Description: A resource exhaustion issue was addressed with improved input validation.

CVE-2018-4381: Angel Ramirez

NetworkExtension

Available for: Apple Watch Series 1 and later

Impact: Connecting to a VPN server may leak DNS queries to a DNS proxy

Description: A logic issue was addressed with improved state management.

CVE-2018-4369: an anonymous researcher

Safari Reader

Available for: Apple Watch Series 1 and later

Impact: Enabling the Safari Reader feature on a maliciously crafted webpage may lead to universal cross site scripting

Description: A logic issue was addressed with improved validation.

CVE-2018-4374: Ryan Pickren (ryanpickren.com)

Safari Reader

Available for: Apple Watch Series 1 and later

Impact: Enabling the Safari Reader feature on a maliciously crafted webpage may lead to universal cross site scripting

Description: A cross-site scripting issue existed in Safari. This issue was addressed with improved URL validation.

CVE-2018-4377: Ryan Pickren (ryanpickren.com)

Security

Available for: Apple Watch Series 1 and later

Impact: Processing a maliciously crafted S/MIME signed message may lead to a denial of service

Description: A validation issue was addressed with improved logic.

CVE-2018-4400: Yukinobu Nagayasu of LAC Co., Ltd.

WebKit

Available for: Apple Watch Series 1 and later

Impact: Processing maliciously crafted web content may lead to arbitrary code execution

Description: Multiple memory corruption issues were addressed with improved memory handling.

CVE-2018-4372: HyungSeok Han, DongHyeon Oh, and Sang Kil Cha of KAIST Softsec Lab, Korea

CVE-2018-4373: ngg, alippai, DirtYiCE, KT of Tresorit working with Trend Micro’s Zero Day Initiative

CVE-2018-4375: Yu Haiwan and Wu Hongjun From Nanyang Technological University working with Trend Micro's Zero Day Initiative

CVE-2018-4376: 010 working with Trend Micro's Zero Day Initiative

CVE-2018-4382: lokihardt of Google Project Zero

CVE-2018-4386: lokihardt of Google Project Zero

CVE-2018-4392: zhunki of 360 ESG Codesafe Team

CVE-2018-4416: lokihardt of Google Project Zero

WebKit

Available for: Apple Watch Series 1 and later

Impact: Processing maliciously crafted web content may lead to code execution

Description: A memory corruption issue was addressed with improved validation.

CVE-2018-4378: HyungSeok Han, DongHyeon Oh, and Sang Kil Cha of KAIST Softsec Lab, Korea, zhunki of 360 ESG Codesafe Team

Wi-Fi

Available for: Apple Watch Series 1 and later

Impact: An attacker in a privileged position may be able to perform a denial of service attack

Description: A denial of service issue was addressed with improved validation.

CVE-2018-4368: Milan Stute and Alex Mariotto of Secure Mobile Networking Lab at Technische Universität Darmstadt

Additional recognition

Certificate Signing

We would like to acknowledge Yiğit Can YILMAZ (@yilmazcanyigit) for their assistance.

coreTLS

We would like to acknowledge Eyal Ronen (Weizmann Institute), Robert Gillham (University of Adelaide), Daniel Genkin (University of Michigan), Adi Shamir (Weizmann Institute), David Wong (NCC Group), and Yuval Yarom (University of Adelaide and Data61) for their assistance.

Safari Reader

We would like to acknowledge Ryan Pickren (ryanpickren.com) for their assistance.

Security

We would like to acknowledge Marinos Bernitsas of Parachute for their assistance.