Fetchmail before 6.4.22 fails to enforce STARTTLS session encryption in some circumstances, such as a certain situation with IMAP and PREAUTH.

**Why TLS is better without STARTTLS  
A Security Analysis of STARTTLS in the Email Context**

by Damian Poddebniak¹, Fabian Ising¹, Hanno Böck², and Sebastian Schinzel¹

¹ Münster University of Applied Sciences ² Independent Researcher

_Full paper published at USENIX Security 21_

**Introduction**

Connections between email clients and servers provide two ways to be protected with TLS: While implicit TLS encrypts the connection from the start and runs on a separate port, STARTTLS provides a mechanism to upgrade existing unencrypted connections to TLS.

Sometimes STARTTLS is seen as an opportunistic encryption mode that provides TLS protection only when available. This is trivially vulnerable to downgrade attacks. However, modern email clients usually have the expectation that STARTTLS is enforced, and when enabled, no unencrypted communication is possible.

Upgrading connections via STARTTLS is fragile and vulnerable to a number of security vulnerabilities and attacks. We found more than 40 vulnerabilities in STARTTLS implementations. We conclude that these vulnerabilities are so common that we recommend to avoid using STARTTLS when possible.

**Attacks**

We assume a Meddler-in-the-Middle (MitM) attacker who can modify connections established between an email client and the email server of an provider.

**Stealing Login Credentials with SMTP and IMAP via Command Injection**

In 2011 Postfix developer Wietse Venema described a bug in STARTTLS implementations that allowed injecting plaintext commands that a server interprets as if they were part of the encrypted connection. This works by sending additional commands with the STARTTLS command to the server in the same TCP segment.

We found that despite being known since 2011, this vulnerability is still very common. We found 15 vulnerable implementations, and in scans, 2% of all mail servers showed this vulnerability.

This command injection can be used to steal credentials with the SMTP and IMAP protocols.

Our attack requires a Meddler in the Middle (MitM) attacker that can modify network traffic and has login credentials for their own account on the same server. The attacker can inject commands that authenticate them and then start sending (SMTP) or storing (IMAP) an email. The login credentials sent by the victim will be stored in the email that the attacker can access.

The command injection can also be used for a cross-protocol attack to serve HTTPS content with the mail server's certificate. Detailed descriptions of these attacks can be found in our paper.

**Mailbox content forgery via Response Injection**

We discovered an attack similar to the command injection in email client applications. We call this a response injection. This bug affected many popular mail clients, including Apple Mail, Mozilla Thunderbird, Claws Mail, and Mutt.

By injecting additional content to the server message in response to the STARTTLS command before the TLS handshake, we can inject server commands that the client will process as if they were part of the encrypted connection. This can be used to forge mailbox content.

**IMAP connection downgrade via PREAUTH and credential-stealing with REFERRAL**

In the IMAP protocol, a server can signal the client in the first message that it is already authenticated via the PREAUTH command. The protocol forbids using the STARTTLS command in an authenticated state. Therefore if a client application accepts PREAUTH, it cannot enforce STARTTLS.

A Meddler in the Middle attacker can use this to prevent STARTTLS from upgrading the connection and force a client to an unencrypted connection.

This vulnerability was originally found in Trojitá in 2014. We discovered that multiple other email client applications were vulnerable to the same bug.

This bug is especially severe in combination with the IMAP features Login Referrals and Mailbox Referrals. These commands allow a server to instruct a client to log into another IMAP server. By using PREAUTH to prevent an encrypted connection, an attacker can use referrals to force a client to send credentials to an attacker-controlled server. Fortunately, the referral features are not supported by many clients. We found only one client - Alpine - vulnerable to this combination of PREAUTH and referrals.

**Additional Attacks**

We found additional attacks, whose security impact may vary for implementations. Please see our paper to learn more about these attacks.

**Conclusion**

All vulnerabilities described here rely on the transition of an insecure connection to a secure connection. Implicit TLS does not have such a transition and is therefore not vulnerable to any of these attacks. We therefore consider implicit TLS a more secure option than STARTTLS.

We also point out that STARTTLS always introduces at least one extra connection round trip. So implicit TLS generally provides better performance.

**Impact**

The demonstrated attacks require an active attacker and may be recognized when used against an email client that tries to enforce the transition to TLS. We have informed all popular email client and server vendors and most issues are already fixed. We think that the demonstrated attacks would be difficult to execute on a large scale and we primarily expect them to be used in targeted attacks. As a general recommendation you should always update your software and (to also profit from faster connections) reconfigure your email client to use implicit TLS only (see below).

**Recommendations****For Email Client Users**

If possible, we recommend that users check and configure their email clients to use SMTP, POP3 and IMAP with implicit TLS on dedicated ports, i.e., SMTP/Submission on port 465, POP3 on port 995, and IMAP on port 993. This is in line with already existing recommendations in RFC 8314 and was already recommended by security professionals before.

Some mail service providers, notably Microsoft and Apple, do not support implicit TLS for SMTP/Submission. We recommend that users ask their mail service providers to offer the more secure implicit TLS option.

**For Application Developers**

Both email server and client applications should offer implicit TLS by default. In the long term software developers may decide to not support STARTTLS at all and thus simplify both their code and configuration dialogs and files.

We recommend auditing all applications supporting STARTTLS - both on the server and the client side - for the bugs discovered. Most importantly, applications need to ensure that no unencrypted content gets processed as part of an encrypted connection. IMAP applications must make sure that they do not allow PREAUTH in combination with STARTTLS. We provide the EAST toolkit, which allows testing applications.

**For Mail Server Administrators**

Make sure your server supports implicit TLS for all supported protocols. If possible, consider disabling STARTTLS for IMAP, POP3 and SMTP submission.

If you really need to support STARTTLS, we recommend testing your server with our tool for the command injection vulnerability for all supported protocols. If your server software is vulnerable, you should ask your vendor for a security update.

**FAQ****Isn't STARTTLS insecure anyway?**

STARTTLS is used in two "modes", "opportunistic", and "enforced". Email clients must authenticate themselves with a username and password before submitting a new email or accessing existing emails. For these connections, the transition to TLS via STARTTLS **must** be strictly enforced because a downgrade would reveal the username and password and give an attacker full access to the email account.

**How can I test if my software is vulnerable?**

We provide the EAST toolkit that allows testing email clients and servers.

**Testing an email server** for the command injection is relatively easy with our Command Injection Tester. testssl.sh (dev version) and TLS-Attacker/TLS-Scanner (starttls branch) also check for the command injection.

**Testing an email client** is more complex, and we refer to EAST's Fake Mail Server component.

**Are other protocols with support for STARTTLS or similar mechanisms affected?**

We expect to see similar vulnerabilities in other protocols using STARTTLS, e.g., XMPP, FTP, IRC, or LDAP. Thus our recommendation to avoid STARTTLS and use implicit TLS when possible applies to those protocols as well. We encourage security researchers to look for such vulnerabilities in other protocols.

Some protocols only support STARTTLS and provide no implicit TLS mechanism. We recommend that standards bodies define implicit TLS modes for these protocols and that future protocols do this by default and avoid STARTTLS completely.

**What about communication between email servers (MTA to MTA)?**

Traditionally, STARTTLS between email servers only protects against passive attacks and is vulnerable to active attacks such as STARTTLS stripping. Thus STARTTLS vulnerabilities do not give an advantage to the attacker.

However, efforts like MTA-STS and DANE provide authentication mechanisms for MTA to MTA connections. Therefore server software should be investigated for STARTTLS vulnerabilities as well. Particularly relevant are the buffering bugs, which can happen both for the sending (response injection) and receiving (command injection) side of a mail server. We have found and reported some vulnerabilities in server software during our research.

Currently, there is no standardized way to use implicit TLS for MTA to MTA connections. Therefore, it is not possible to avoid STARTTLS without changes to the protocol specification.

**How important is this?**

It's not the most important thing you should worry about today.

**How can I contact you?**

You can reach us via mail or twitter:

*   Damian Poddebniak, @dues\_\_, poddebniak@fh-muenster.de
*   Fabian Ising, @Murgi, F.Ising@fh-muenster.de
*   Hanno Böck, @hanno, hanno@hboeck.de
*   Sebastian Schinzel, @seecurity, schinzel@fh-muenster.de

**Reported Vulnerabilities**

The following is a list of all STARTTLS-related vulnerabilities we found during our research. None of the issues would be present if implicit TLS would have been used exclusively. Due to different kinds of reports, not all issues are publicly documented. All issues were reported more than than 90 days ago.

**Email Clients**

As an end user, make sure to use the newest version of your email software. The following list serves as a quick check if your client is still affected.

**Response Injection (Buffering)**

Product

Protocol

Status

Links

Apple Mail (macOS)

SMTP/POP3/IMAP

Fixed in macOS High Sierra 10.13.6/Big Sur 11.4

CVE-2020-9941, CVE-2021-30696

Apple Mail (iOS/iPadOS)

SMTP/POP3/IMAP

Fixed in iOS/iPadOS 14.0

CVE-2020-9941

Mozilla Thunderbird

IMAP

Fixed in 78.7.0

CVE-2020-15685, Vendor advisory, Bug report

Claws Mail

SMTP/POP3/IMAP

Fixed in 3.17.6 for SMTP/POP3, See libEtPan for IMAP

CVE-2020-15917

Mutt

IMAP/SMTP/POP3

Fixed in 1.14.4

CVE-2020-14954

NeoMutt

IMAP/SMPT/POP3

Fixed in 2020-06-19

Commit/Patch, see also CVE-2020-14954

Evolution

SMTP/POP3

Fixed in 3.36.4 (evolution-data-server)

CVE-2020-14928

LibEtPan (Mail Framework for C Language)

IMAP/SMTP/POP3

Fixed in repository, unreleased

CVE-2020-15953

Exim (MTA sending)

SMTP

Unfixed (reported privately)

CVE-2021-38371

Gmail (iOS/iPadOS)

SMTP/IMAP

Unfixed (reported privately)

\-

Mail.ru, MyMail

SMTP

Unfixed (reported privately, report closed as not applicable)

\-

Yandex

SMTP/IMAP

Unfixed (reported privately)

\-

PHP (stream\_socket\_enable\_crypto)

SMTP/POP3/IMAP

Unfixed

Bug report (private)

**Negotiation and Tampering bugs**

Product

Description

Protocol

Status

Links

Gmail (Android)

Leak of emails

IMAP

Fixed (retested in 2021.07.11.387440246)

\-

Gmail (Go)

Leak of emails

IMAP

Fixed (retested in 2020.10.15.341102866)

\-

Samsung Email

Leak of emails

IMAP

Fixed (untested)

\-

Alpine

Untagged responses accepted before STARTTLS

IMAP

Unknown (reported via email)

\-

Trojitá Trojita

Untagged responses accepted before STARTTLS

IMAP

Unknown

Bug report

Mozilla Thunderbird

Server responses prior to STARTTLS processed

IMAP

Fixed in 78.12

CVE-2021-29969, Vendor advisory

KMail

STARTTLS ignored when "Server requires authentication" not checked

SMTP

Unfixed

Bug report

Sylpheed

STARTTLS stripping

IMAP

Unknown

Bug report

OfflineIMAP

STARTTLS stripping

IMAP

Unknown

Bug report

GMX / Web.de Mail Collector

STARTTLS stripping

POP3/IMAP

Fixed

\-

Mail.ru, MyMail, Email app for Gmail

STARTTLS Stripping

SMTP

Unfixed (report closed as not applicable)

\-

**Avoiding Encryption via IMAP PREAUTH**

Product

Status

Links

Apple Mail (iOS/iPadOS)

Fixed in iOS 15.1

\-

Mozilla Thunderbird

Fixed in 68.9.0

CVE-2020-12398

Alpine

Fixed in 2.23

CVE-2020-14929, Commit

Mutt

Fixed in 1.14.3

CVE-2020-14093

NeoMutt

Fixed in Release 2020-06-19

Commit/Patch, see also CVE-2020-14093

GMX / Web.de Mail Collector

Fixed

\-

**Certificate Validation**

Product

Protocol

Description

Status

Links

OfflineIMAP

IMAP

Accepts untrusted certificates

Unknown

Bug report

GMX / Web.de Mail Collector

POP3/IMAP

Accepts untrusted certificates

Still allows self-signed

\-

Yandex

SMTP/IMAP

Accepts untrusted certificates

Unknown (report closed as not eligible)

\-

Mail.ru, MyMail

SMTP

Accepts untrusted certificates (SMTP, IMAP)

Unknown (report closed as duplicate)

\-

Outlook (Android & iOS)

SMTP/IMAP

Certificate hostname not checked (SMTP, IMAP)

Unknown (report closed as low/medium severity)

\-

Geary

SMTP/IMAP

Accepting an untrusted certificate creates a permanent trust exception for all certificates

Fixed in 3.36.3

CVE-2020-24661

Trojitá Trojita

SMTP

Accepts untrusted certificates

Fixed in repository (77ddd5d4) (no official releases)

CVE-2020-15047

Ruby Net::SMTP

SMTP

Only checks hostname, ignores certificate signature

Fixed in 2.7.2

Bug report

**Crashes**

Product

Protocol

Description

Status

Links

Alpine

IMAP

Crash when LIST or LSUB send before STARTTLS

Unknown (reported via email)

\-

Balsa

IMAP

Nullptr dereference when TLS required and PREAUTH send

Fixed in 2.5.10

CVE-2020-16118

Balsa

IMAP

Stack overflow due to repeated BAD answer to CAPABILITY command

Fixed in 2.6.3

Bug Report

Balsa

IMAP

Crash on untagged EXPUNGE response

Fixed in 2.6.3

Bug Report

Evolution

IMAP

Invalid free when no auth mechanisms in greeting

Fixed in >3.35.91

CVE-2020-16117

**Miscellaneous**

Product

Protocol

Description

Status

Links

KMail

POP3

Setup wizard in POP3 defaults to unencrypted connections

Unfixed

Bug Report

KMail

POP3

Config shows "encrypted", but it isn't

Unfixed

CVE-2020-15954

KMail

SMTP/IMAP

Dialog loop "forces" the user to accept invalid certificates

Unfixed

Bug Report

Mozilla Thunderbird

POP3

Infinite loop when POP3 server replies with -ERR to STLS command

Unknown

Bug Report

Trojitá Trojita

SMTP/IMAP

Hard to choose implicit TLS due to typo (German)

Fixed

Bug Report

Trojitá Trojita

SMTP

SMTP defaults to plaintext on port 587

Unknown

Bug Report

**Email Servers**

We found 320.000 vulnerable email servers in an Internet-wide scan and conducted a coordinated disclosure involving different CERTs. It is impracticable to inform and keep track of the update process of all mail service providers on the Internet, and thus we identified and prioritized popular mail service providers. We only list these in the following table.

Server issues are generally more severe than client issues. Unfortunately, no client configuration prevents server issues from being exploited, not even the usage of implicit TLS. Thus, you must ensure that your server (or your mail service provider) is not affected by STARTTLS issues.

You can use our command\_injection\_tester tool to verify that your server is not affected by the most severe issue.

**Command Injection (Buffering)**

Product

Protocol

Status

Links

Nemesis (used by GMX / Web.de, provider)

POP3/IMAP

Fixed (reported privately)

\-

Interia.pl (provider)

SMTP/POP3/IMAP

Fixed (reported privately)

\-

Yahoo (only MTA-to-MTA, provider)

SMTP

Unfixed (reported privately)

\-

Yandex (provider)

SMTP/POP3/IMAP

Unfixed (reported privately)

\-

s/qmail

SMTP

Fixed in 4.0.09

CVE-2020-15955

Coremail

SMTP/POP3/IMAP

Unfixed (reported via CERT)

\-

Citadel

SMTP/POP3/IMAP

Unfixed

CVE-2020-29547, Bug report

Gordano GMS

POP3/IMAP

Unfixed

CVE-2021-37844

recvmail

SMTP

Fixed in 3.1.2 (reported privately)

\-

SmarterMail

POP3

Fixed in Build 7537

CVE-2020-29548

Burp Collaborator

SMTP

Fixed in 2020.9.2

Bug report, Vendor release notes

Dovecot

SMTP

Fixed in 2.3.14.1 and 2.3.15

CVE-2021-33515

Mercury/32

SMTP/POP3/IMAP

Fixed in 4.90

CVE-2021-33487

QMail Toaster (1.4.1)

SMTP

Project discontinued

\-

Courier

POP3

Fixed in 1.1.5 (reported privately), known since 2013

Discussion from 2013, CVE-2021-38084, Fix

PHP (stream\_socket\_enable\_crypto)

SMTP/POP3/IMAP

Unfixed

Bug report (private)

**Session Fixation**

Product

Protocol

Status

Links

Citadel

POP3/IMAP

Reported via forum, unfixed

Forum with report, CVE-2021-37845

IPswitch iMail

POP3/IMAP

Fixed in iMail 12.5.8

CVE-2021-37846, Changelog

**Miscellaneous Issues**

Product

Protocol

Description

Status

Links

Nemesis (used by GMX / Web.de, provider)

SMTP

Advertises authentication before STARTTLS even though it is disabled

Fixed (reported via Bugbounty)

\-

**Media reports**

Golem.de: Sicherheitsrisiko STARTTLS  
The Hacker News: Dozens of STARTTLS Related Flaws Found Affecting Popular Email Clients  
The Record: STARTTLS implementations in email clients & servers plagued by 40+ vulnerabilities  
SecurityLab.ru: Десятки уязвимостей в протоколе STARTTLS затрагивают популярные почтовые клиенты  
LWN: STARTTLS considered harmful  
Bulletproof TLS Newsletter: Vulnerabilities show fragility of STARTTLS  
APNIC blog: Vulnerabilities show why STARTTLS should be avoided if possible  

**Presentations**

USENIX Security '21 - Why TLS is better without STARTTLS  
Driving IT Conference 2021: STARTTLS endangers your E-Mail passwords  

**Followup research**

After we published our research some people found similar bugs in other protocols using STARTTLS.

StartTLS in LDAP  
nbdkit: Reset structured replies on STARTTLS (CVE-2021-3716)  
fetchmail: STARTTLS session encryption bypassing (CVE-2021-39272)  
curl 7.79.0 fixes two STARTTLS vulnerabilities  
CVE-2021-38542: Apache James vulnerable to STARTTLS command injection (IMAP and POP3)

CVE-2021-39272: NO STARTTLS

The issue was addressed with improved permissions logic. This issue is fixed in macOS Monterey 12.0.1, macOS Big Sur 11.6.1. An unprivileged application may be able to edit NVRAM variables.

CVE-2021-30913: About the security content of macOS Monterey 12.0.1

Multiple out-of-bounds write issues were addressed with improved bounds checking. This issue is fixed in macOS Big Sur 11.6.1. A malicious application may be able to execute arbitrary code with kernel privileges.

Released October 25, 2021

**AppleScript**

Available for: macOS Big Sur

Impact: Processing a maliciously crafted AppleScript binary may result in unexpected application termination or disclosure of process memory

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

CVE-2021-30876: Jeremy Brown, hjy79425575

CVE-2021-30879: Jeremy Brown, hjy79425575

CVE-2021-30877: Jeremy Brown

CVE-2021-30880: Jeremy Brown

**Audio**

Available for: macOS Big Sur

Impact: A malicious application may be able to elevate privileges

Description: An integer overflow was addressed through improved input validation.

CVE-2021-30907: Zweig of Kunlun Lab

**Bluetooth**

Available for: macOS Big Sur

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

Description: A race condition was addressed with improved state handling.

CVE-2021-30899: Weiteng Chen, Zheng Zhang, and Zhiyun Qian of UC Riverside, and Yu Wang of Didi Research America

**ColorSync**

Available for: macOS Big Sur

Impact: Processing a maliciously crafted image may lead to arbitrary code execution

Description: A memory corruption issue in the processing of ICC profiles was addressed with improved input validation.

CVE-2021-30926: Jeremy Brown

Entry added May 25, 2022

**ColorSync**

Available for: macOS Big Sur

Impact: Processing a maliciously crafted image may lead to arbitrary code execution

Description: A memory corruption issue existed in the processing of ICC profiles. This issue was addressed with improved input validation.

CVE-2021-30917: Alexandru-Vlad Niculae and Mateusz Jurczyk of Google Project Zero

**Continuity Camera**

Available for: macOS Big Sur

Impact: A local attacker may be able to cause unexpected application termination or arbitrary code execution

Description: An uncontrolled format string issue was addressed with improved input validation.

CVE-2021-30903: Gongyu Ma of Hangzhou Dianzi University

Entry added January 19, 2022, updated May 25, 2022

**CoreAudio**

Available for: macOS Big Sur

Impact: Processing a maliciously crafted file may disclose user information

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

CVE-2021-30905: Mickey Jin (@patch1t) of Trend Micro

Entry added January 19, 2022

**CoreGraphics**

Available for: macOS Big Sur

Impact: Processing a maliciously crafted PDF may lead to arbitrary code execution

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

CVE-2021-30919

**FileProvider**

Available for: macOS Big Sur

Impact: Unpacking a maliciously crafted archive may lead to arbitrary code execution

Description: An input validation issue was addressed with improved memory handling.

CVE-2021-30881: Simon Huang (@HuangShaomang) and pjf of IceSword Lab of Qihoo 360

**GPU Drivers**

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-2021-30900: Yinyi Wu (@3ndy1) of Ant Security Light-Year Lab

Entry added January 19, 2022

**iCloud**

Available for: macOS Big Sur

Impact: A local attacker may be able to elevate their privileges

Description: This issue was addressed with improved checks.

CVE-2021-30906: Cees Elzinga

**Intel Graphics Driver**

Available for: macOS Big Sur

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

Description: A memory corruption issue was addressed with improved state management.

CVE-2021-30824: Antonio Zekic (@antoniozekic) of Diverto

**Intel Graphics Driver**

Available for: macOS Big Sur

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

Description: Multiple out-of-bounds write issues were addressed with improved bounds checking.

CVE-2021-30901: Zuozhi Fan (@pattern\_F\_) of Ant Security TianQiong Lab, Jack Dates of RET2 Systems, Inc., Liu Long of Ant Security Light-Year Lab, Yinyi Wu (@3ndy1) of Ant Security Light-Year Lab

CVE-2021-30922: Jack Dates of RET2 Systems, Inc., Yinyi Wu (@3ndy1)

Entry updated January 19, 2022, updated May 25, 2022

**IOGraphics**

Available for: macOS Big Sur

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

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

CVE-2021-30821: Tim Michaud (@TimGMichaud) of Zoom Video Communications

**IOMobileFrameBuffer**

Available for: macOS Big Sur

Impact: An application may be able to execute arbitrary code with kernel privileges. Apple is aware of a report that this issue may have been actively exploited.

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

CVE-2021-30883: an anonymous researcher

**Kernel**

Available for: macOS Big Sur

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-2021-30909: Zweig of Kunlun Lab

**Kernel**

Available for: macOS Big Sur

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

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

CVE-2021-30916: Zweig of Kunlun Lab

**Model I/O**

Available for: macOS Big Sur

Impact: Processing a maliciously crafted file may disclose user information

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

CVE-2021-30910: Mickey Jin (@patch1t) of Trend Micro

**Model I/O**

Available for: macOS Big Sur

Impact: Processing a maliciously crafted USD file may disclose memory contents

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

CVE-2021-30911: Rui Yang and Xingwei Lin of Ant Security Light-Year Lab

**SMB**

Available for: macOS Big Sur

Impact: A remote attacker may be able to leak memory

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

CVE-2021-30844: Peter Nguyen Vu Hoang of STAR Labs

Entry added May 25, 2022

**SMB**

Available for: macOS Big Sur

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

Description: A race condition was addressed with improved locking.

CVE-2021-30868: Peter Nguyen Vu Hoang of STAR Labs

**SoftwareUpdate**

Available for: macOS Big Sur

Impact: An unprivileged application may be able to edit NVRAM variables

Description: A logic issue was addressed with improved restrictions.

CVE-2021-30913: Kirin (@Pwnrin) and chenyuwang (@mzzzz\_\_) of Tencent Security Xuanwu Lab

Entry updated May 25, 2022

**SoftwareUpdate**

Available for: macOS Big Sur

Impact: A malicious application may gain access to a user's Keychain items

Description: The issue was addressed with improved permissions logic.

CVE-2021-30912: Kirin (@Pwnrin) and chenyuwang (@mzzzz\_\_) of Tencent Security Xuanwu Lab

**UIKit**

Available for: macOS Big Sur

Impact: A person with physical access to a device may be able to determine characteristics of a user's password in a secure text entry field

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

CVE-2021-30915: Kostas Angelopoulos

**Windows Server**

Available for: macOS Big Sur

Impact: A local attacker may be able to view the previous logged-in user’s desktop from the fast user switching screen

Description: An authentication issue was addressed with improved state management.

CVE-2021-30908: ASentientBot

**xar**

Available for: macOS Big Sur

Impact: Unpacking a maliciously crafted archive may allow an attacker to write arbitrary files

Description: This issue was addressed with improved checks.

CVE-2021-30833: Richard Warren of NCC Group

Entry added January 19, 2022

**zsh**

Available for: macOS Big Sur

Impact: A malicious application may be able to modify protected parts of the file system

Description: An inherited permissions issue was addressed with additional restrictions.

CVE-2021-30892: Jonathan Bar Or of Microsoft

CVE-2021-30922: About the security content of macOS Big Sur 11.6.1

This issue was addressed with improved checks. This issue is fixed in iOS 15.1 and iPadOS 15.1, macOS Monterey 12.0.1, tvOS 15.1, watchOS 8.1, macOS Big Sur 11.6.1. A local attacker may be able to elevate their privileges.

Released October 25, 2021

**Audio**

Available for: Apple TV 4K and Apple TV HD

Impact: A malicious application may be able to elevate privileges

Description: An integer overflow was addressed through improved input validation.

CVE-2021-30907: Zweig of Kunlun Lab

**ColorSync**

Available for: Apple TV 4K and Apple TV HD

Impact: Processing a maliciously crafted image may lead to arbitrary code execution

Description: A memory corruption issue existed in the processing of ICC profiles. This issue was addressed with improved input validation.

CVE-2021-30917: Alexandru-Vlad Niculae and Mateusz Jurczyk of Google Project Zero

**Continuity Camera**

Available for: Apple TV 4K and Apple TV HD

Impact: A local attacker may be able to cause unexpected application termination or arbitrary code execution

Description: An uncontrolled format string issue was addressed with improved input validation.

CVE-2021-30903: Gongyu Ma of Hangzhou Dianzi University

Entry added May 25, 2022

**CoreAudio**

Available for: Apple TV 4K and Apple TV HD

Impact: Processing a maliciously crafted file may disclose user information

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

CVE-2021-30905: Mickey Jin (@patch1t) of Trend Micro

**CoreGraphics**

Available for: Apple TV 4K and Apple TV HD

Impact: Processing a maliciously crafted PDF may lead to arbitrary code execution

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

CVE-2021-30919

**FileProvider**

Available for: Apple TV 4K and Apple TV HD

Impact: A malicious application may be able to bypass Privacy preferences

Description: A permissions issue was addressed with improved validation.

CVE-2021-31007: Csaba Fitzl (@theevilbit) of Offensive Security

Entry added March 31, 2022, updated May 25, 2022

**FileProvider**

Available for: Apple TV 4K and Apple TV HD

Impact: Unpacking a maliciously crafted archive may lead to arbitrary code execution

Description: An input validation issue was addressed with improved memory handling.

CVE-2021-30881: Simon Huang (@HuangShaomang) and pjf of IceSword Lab of Qihoo 360

**Game Center**

Available for: Apple TV 4K and Apple TV HD

Impact: A malicious application may be able to access information about a user's contacts

Description: A logic issue was addressed with improved restrictions.

CVE-2021-30895: Denis Tokarev (@illusionofcha0s)

Entry updated May 25, 2022

**Game Center**

Available for: Apple TV 4K and Apple TV HD

Impact: A malicious application may be able to read user's gameplay data

Description: A logic issue was addressed with improved restrictions.

CVE-2021-30896: Denis Tokarev (@illusionofcha0s)

Entry updated May 25, 2022

**iCloud**

Available for: Apple TV 4K and Apple TV HD

Impact: A local attacker may be able to elevate their privileges

Description: This issue was addressed with improved checks.

CVE-2021-30906: Cees Elzinga

**Image Processing**

Available for: Apple TV 4K and Apple TV HD

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

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

CVE-2021-30894: Pan ZhenPeng (@Peterpan0927) of Alibaba Security Pandora Lab

**IOMobileFrameBuffer**

Available for: Apple TV 4K and Apple TV HD

Impact: An application may be able to execute arbitrary code with kernel privileges. Apple is aware of a report that this issue may have been actively exploited.

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

CVE-2021-30883: an anonymous researcher

**Kernel**

Available for: Apple TV 4K and Apple TV HD

Impact: A remote attacker can cause a device to unexpectedly restart

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

CVE-2021-30924: Elaman Iskakov (@darling\_x0r) of Effective and Alexey Katkov (@watman27)

Entry added January 19, 2022

**Kernel**

Available for: Apple TV 4K and Apple TV HD

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

Description: A use after free issue was addressed with improved memory management.

CVE-2021-30886: @0xalsr

**Kernel**

Available for: Apple TV 4K and Apple TV HD

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-2021-30909: Zweig of Kunlun Lab

**Model I/O**

Available for: Apple TV 4K and Apple TV HD

Impact: Processing a maliciously crafted file may disclose user information

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

CVE-2021-30910: Mickey Jin (@patch1t) of Trend Micro

**UIKit**

Available for: Apple TV 4K and Apple TV HD

Impact: A person with physical access to a device may be able to determine characteristics of a user's password in a secure text entry field

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

CVE-2021-30915: Kostas Angelopoulos

**WebKit**

Available for: Apple TV 4K and Apple TV HD

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

Description: A type confusion issue was addressed with improved memory handling.

CVE-2021-31008

Entry added March 31, 2022

**WebKit**

Available for: Apple TV 4K and Apple TV HD

Impact: Processing maliciously crafted web content may lead to unexpectedly unenforced Content Security Policy

Description: A logic issue was addressed with improved restrictions.

CVE-2021-30887: Narendra Bhati (@imnarendrabhati) of Suma Soft Pvt. Ltd.

**WebKit**

Available for: Apple TV 4K and Apple TV HD

Impact: A malicious website using Content Security Policy reports may be able to leak information via redirect behavior 

Description: An information leakage issue was addressed.

CVE-2021-30888: Prakash (@1lastBr3ath)

**WebKit**

Available for: Apple TV 4K and Apple TV HD

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

Description: A buffer overflow issue was addressed with improved memory handling.

CVE-2021-30889: Chijin Zhou of ShuiMuYuLin Ltd and Tsinghua wingtecher lab

**WebKit**

Available for: Apple TV 4K and Apple TV HD

Impact: Processing maliciously crafted web content may lead to universal cross site scripting

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

CVE-2021-30890: an anonymous researcher

CVE-2021-30906: About the security content of tvOS 15.1

A buffer overflow issue was addressed with improved memory handling. This issue is fixed in macOS Monterey 12.1, watchOS 8.3, iOS 15.2 and iPadOS 15.2, tvOS 15.2. Processing a maliciously crafted audio file may lead to arbitrary code execution.

Released December 13, 2021

**Audio**

Available for: Apple Watch Series 3 and later

Impact: Parsing a maliciously crafted audio file may lead to disclosure of user information

Description: A buffer overflow issue was addressed with improved memory handling.

CVE-2021-30960: JunDong Xie of Ant Security Light-Year Lab

**CFNetwork Proxies**

Available for: Apple Watch Series 3 and later

Impact: User traffic might unexpectedly be leaked to a proxy server despite PAC configurations

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

CVE-2021-30966: Michal Rajcan of Jamf, Matt Vlasach of Jamf (Wandera)

**ColorSync**

Available for: Apple Watch Series 3 and later

Impact: Processing a maliciously crafted image may lead to arbitrary code execution

Description: A memory corruption issue in the processing of ICC profiles was addressed with improved input validation.

CVE-2021-30926: Jeremy Brown

CVE-2021-30942: Mateusz Jurczyk of Google Project Zero

**CoreAudio**

Available for: Apple Watch Series 3 and later

Impact: Processing a maliciously crafted audio file may lead to arbitrary code execution

Description: A buffer overflow was addressed with improved memory handling.

CVE-2021-30957: JunDong Xie of Ant Security Light-Year Lab

Entry updated May 25, 2022

**CoreAudio**

Available for: Apple Watch Series 3 and later

Impact: Playing a malicious audio file may lead to arbitrary code execution

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

CVE-2021-30958: JunDong Xie of Ant Security Light-Year Lab

**Crash Reporter**

Available for: Apple Watch Series 3 and later

Impact: A local attacker may be able to elevate their privileges

Description: This issue was addressed with improved checks.

CVE-2021-30945: Zhipeng Huo (@R3dF09) and Yuebin Sun (@yuebinsun2020) of Tencent Security Xuanwu Lab (xlab.tencent.com)

**Game Center**

Available for: Apple Watch Series 3 and later

Impact: A malicious application may be able to read sensitive contact information

Description: A permissions issue was addressed with improved validation.

CVE-2021-31000: Denis Tokarev (@illusionofcha0s)

Entry added May 25, 2022

**ImageIO**

Available for: Apple Watch Series 3 and later

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-2021-30939: Mickey Jin (@patch1t) of Trend Micro, Jaewon Min of Cisco Talos, Rui Yang and Xingwei Lin of Ant Security Light-Year Lab

Entry updated May 25, 2022

**Kernel**

Available for: Apple Watch Series 3 and later

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

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

CVE-2021-30916: Zweig of Kunlun Lab

**Kernel**

Available for: Apple Watch Series 3 and later

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

Description: A memory corruption vulnerability was addressed with improved locking.

CVE-2021-30937: Sergei Glazunov of Google Project Zero

**Kernel**

Available for: Apple Watch Series 3 and later

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

Description: A use after free issue was addressed with improved memory management.

CVE-2021-30927: Xinru Chi of Pangu Lab

CVE-2021-30980: Xinru Chi of Pangu Lab

**Kernel**

Available for: Apple Watch Series 3 and later

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

Description: A memory corruption issue was addressed with improved state management.

CVE-2021-30949: Ian Beer of Google Project Zero

**Kernel**

Available for: Apple Watch Series 3 and later

Impact: An attacker in a privileged network position may be able to execute arbitrary code

Description: A buffer overflow issue was addressed with improved memory handling.

CVE-2021-30993: OSS-Fuzz, Ned Williamson of Google Project Zero

**Kernel**

Available for: Apple Watch Series 3 and later

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

Description: A race condition was addressed with improved state handling.

CVE-2021-30955: Zweig of Kunlun Lab

**Messages**

Available for: Apple Watch Series 3 and later

Impact: A malicious user may be able to leave a messages group but continue to receive messages in that group

Description: An issue in the handling of group membership was resolved with improved logic.

CVE-2021-30943: Joshua Sardella

Entry added May 25, 2022

**Preferences**

Available for: Apple Watch Series 3 and later

Impact: A malicious application may be able to elevate privileges

Description: A race condition was addressed with improved state handling.

CVE-2021-30995: Mickey Jin (@patch1t) of Trend Micro, Mickey Jin (@patch1t)

**Sandbox**

Available for: Apple Watch Series 3 and later

Impact: A malicious application may be able to bypass certain Privacy preferences

Description: A validation issue related to hard link behavior was addressed with improved sandbox restrictions.

CVE-2021-30968: Csaba Fitzl (@theevilbit) of Offensive Security

**Sandbox**

Available for: Apple Watch Series 3 and later

Impact: A malicious application may be able to bypass certain Privacy preferences

Description: A logic issue was addressed with improved restrictions.

CVE-2021-30946: @gorelics

**Sandbox**

Available for: Apple Watch Series 3 and later

Impact: An application may be able to access a user's files

Description: An access issue was addressed with additional sandbox restrictions.

CVE-2021-30947: Csaba Fitzl (@theevilbit) of Offensive Security

**SQLite**

Available for: Apple Watch Series 3 and later

Impact: A malicious app may be able to access data from other apps by enabling additional logging

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

CVE-2021-30944: Wojciech Reguła (@\_r3ggi) of SecuRing

Entry added May 25, 2022

**TCC**

Available for: Apple Watch Series 3 and later

Impact: A local user may be able to modify protected parts of the file system

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

CVE-2021-30767: @gorelics

**TCC**

Available for: Apple Watch Series 3 and later

Impact: A malicious application may be able to bypass Privacy preferences

Description: An inherited permissions issue was addressed with additional restrictions.

CVE-2021-30964: Andy Grant of Zoom Video Communications

**WebKit**

Available for: Apple Watch Series 3 and later

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

Description: A buffer overflow issue was addressed with improved memory handling.

CVE-2021-30934: Dani Biro

**WebKit**

Available for: Apple Watch Series 3 and later

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-2021-30936: Chijin Zhou of ShuiMuYuLin Ltd and Tsinghua wingtecher lab

CVE-2021-30951: Pangu

**WebKit**

Available for: Apple Watch Series 3 and later

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

Description: An integer overflow was addressed with improved input validation.

CVE-2021-30952: @18f and @jq0904 of DBAPP Security‘s weibin lab via Tianfu Cup

Entry updated May 25, 2022

**WebKit**

Available for: Apple Watch Series 3 and later

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

Description: A race condition was addressed with improved state handling.

CVE-2021-30984: Kunlun Lab via Tianfu Cup

Entry updated May 25, 2022

**WebKit**

Available for: Apple Watch Series 3 and later

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

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

CVE-2021-30953: Jianjun Dai of 360 Vulnerability Research Institute via Tianfu Cup

Entry updated May 25, 2022

**WebKit**

Available for: Apple Watch Series 3 and later

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

Description: A type confusion issue was addressed with improved memory handling.

CVE-2021-30954: Kunlun Lab via Tianfu Cup

Entry updated May 25, 2022

CVE-2021-30957: About the security content of watchOS 8.3

An integer overflow was addressed with improved input validation. This issue is fixed in Security Update 2021-005 Catalina, iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6, watchOS 7.6.2. Processing a maliciously crafted PDF may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.

This document describes the security content of watchOS 7.6.2.

**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.

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

For more information about security, see the Apple Product Security page.

**watchOS 7.6.2**

Released September 13, 2021

**CoreGraphics**

Available for: Apple Watch Series 3 and later

Impact: Processing a maliciously crafted PDF may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.

Description: An integer overflow was addressed with improved input validation.

CVE-2021-30860: The Citizen Lab

**Core Telephony**

Available for: Apple Watch Series 3 and later

Impact: A sandboxed process may be able to circumvent sandbox restrictions. Apple was aware of a report that this issue may have been actively exploited at the time of release.

Description: A deserialization issue was addressed through improved validation.

CVE-2021-31010: Citizen Lab and Google Project Zero

Entry added May 25, 2022

Information about products not manufactured by Apple, or independent websites not controlled or tested by Apple, is provided without recommendation or endorsement. Apple assumes no responsibility with regard to the selection, performance, or use of third-party websites or products. Apple makes no representations regarding third-party website accuracy or reliability. Contact the vendor for additional information.

Published Date: May 25, 2022

CVE-2021-30860: About the security content of watchOS 7.6.2

A deserialization issue was addressed through improved validation. This issue is fixed in Security Update 2021-005 Catalina, iOS 12.5.5, iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6, watchOS 7.6.2. A sandboxed process may be able to circumvent sandbox restrictions. Apple was aware of a report that this issue may have been actively exploited at the time of release..

Released September 23, 2021

**CoreGraphics**

Available for: iPhone 5s, iPhone 6, iPhone 6 Plus, iPad Air, iPad mini 2, iPad mini 3, and iPod touch (6th generation)

Impact: Processing a maliciously crafted PDF may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.

Description: An integer overflow was addressed with improved input validation.

CVE-2021-30860: The Citizen Lab

**Core Telephony**

Available for: iPhone 5s, iPhone 6, iPhone 6 Plus, iPad Air, iPad mini 2, iPad mini 3, and iPod touch (6th generation)

Impact: A sandboxed process may be able to circumvent sandbox restrictions. Apple was aware of a report that this issue may have been actively exploited at the time of release.

Description: A deserialization issue was addressed through improved validation.

CVE-2021-31010: Citizen Lab and Google Project Zero

Entry added May 25, 2022

**WebKit**

Available for: iPhone 5s, iPhone 6, iPhone 6 Plus, iPad Air, iPad mini 2, iPad mini 3, and iPod touch (6th generation)

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-2021-30858: an anonymous researcher

**XNU**

Available for: iPhone 5s, iPhone 6, iPhone 6 Plus, iPad Air, iPad mini 2, iPad mini 3, and iPod touch (6th generation)

Impact: A malicious application may be able to execute arbitrary code with kernel privileges. Apple is aware of reports that an exploit for this issue exists in the wild.

Description: A type confusion issue was addressed with improved state handling.

CVE-2021-30869: Erye Hernandez of Google Threat Analysis Group, Clément Lecigne of Google Threat Analysis Group, and Ian Beer of Google Project Zero

CVE-2021-31010: About the security content of iOS 12.5.5

Description: A permissions issue was addressed with improved validation. This issue is fixed in watchOS 7.6, tvOS 14.7, macOS Big Sur 11.5. A malicious application may be able to bypass certain Privacy preferences.

Released July 19, 2021

**Analytics**

Available for: Apple TV 4K and Apple TV HD

Impact: A local attacker may be able to access analytics data

Description: A logic issue was addressed with improved restrictions.

CVE-2021-30871: Denis Tokarev (@illusionofcha0s)

Entry added May 25, 2022

**App Store**

Available for: Apple TV 4K and Apple TV HD

Impact: A malicious application may be able to bypass certain Privacy preferences

Description: A permissions issue was addressed with improved validation.

CVE-2021-31006: Csaba Fitzl (@theevilbit) of Offensive Security

Entry added May 25, 2022

**Audio**

Available for: Apple TV 4K and Apple TV HD

Impact: A local attacker may be able to cause unexpected application termination or arbitrary code execution

Description: This issue was addressed with improved checks.

CVE-2021-30781: tr3e

**AVEVideoEncoder**

Available for: Apple TV 4K and Apple TV HD

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

Description: A memory corruption issue was addressed with improved state management.

CVE-2021-30748: George Nosenko

Entry added January 19, 2022

**CoreAudio**

Available for: Apple TV 4K and Apple TV HD

Impact: Processing a maliciously crafted audio file may lead to arbitrary code execution

Description: A memory corruption issue was addressed with improved state management.

CVE-2021-30775: JunDong Xie of Ant Security Light-Year Lab

**CoreAudio**

Available for: Apple TV 4K and Apple TV HD

Impact: Playing a malicious audio file may lead to an unexpected application termination

Description: A logic issue was addressed with improved validation.

CVE-2021-30776: JunDong Xie of Ant Security Light-Year Lab

**CoreText**

Available for: Apple TV 4K and Apple TV HD

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-2021-30789: Mickey Jin (@patch1t) of Trend Micro, Sunglin of Knownsec 404 team

**Crash Reporter**

Available for: Apple TV 4K and Apple TV HD

Impact: A malicious application may be able to gain root privileges

Description: A logic issue was addressed with improved validation.

CVE-2021-30774:  Yizhuo Wang of Group of Software Security In Progress (G.O.S.S.I.P) at Shanghai Jiao Tong University

**CVMS**

Available for: Apple TV 4K and Apple TV HD

Impact: A malicious application may be able to gain root privileges

Description: An out-of-bounds write issue was addressed with improved bounds checking.

CVE-2021-30780: Tim Michaud(@TimGMichaud) of Zoom Video Communications

**dyld**

Available for: Apple TV 4K and Apple TV HD

Impact: A sandboxed process may be able to circumvent sandbox restrictions

Description: A logic issue was addressed with improved validation.

CVE-2021-30768: Linus Henze (pinauten.de)

**FontParser**

Available for: Apple TV 4K and Apple TV HD

Impact: Processing a maliciously crafted font file may lead to arbitrary code execution

Description: An integer overflow was addressed through improved input validation.

CVE-2021-30760: Sunglin of Knownsec 404 team

**FontParser**

Available for: Apple TV 4K and Apple TV HD

Impact: Processing a maliciously crafted tiff file may lead to a denial-of-service or potentially disclose memory contents

Description: This issue was addressed with improved checks.

CVE-2021-30788: tr3e working with Trend Micro Zero Day Initiative

**FontParser**

Available for: Apple TV 4K and Apple TV HD

Impact: Processing a maliciously crafted font file may lead to arbitrary code execution

Description: A stack overflow was addressed with improved input validation.

CVE-2021-30759: hjy79425575 working with Trend Micro Zero Day Initiative

**Identity Service**

Available for: Apple TV 4K and Apple TV HD

Impact: A malicious application may be able to bypass code signing checks

Description: An issue in code signature validation was addressed with improved checks.

CVE-2021-30773: Linus Henze (pinauten.de)

**Image Processing**

Available for: Apple TV 4K and Apple TV HD

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-2021-30802: Matthew Denton of Google Chrome Security

**ImageIO**

Available for: Apple TV 4K and Apple TV HD

Impact: Processing a maliciously crafted image may lead to arbitrary code execution

Description: This issue was addressed with improved checks.

CVE-2021-30779: Jzhu, Ye Zhang(@co0py\_Cat) of Baidu Security

**ImageIO**

Available for: Apple TV 4K and Apple TV HD

Impact: Processing a maliciously crafted image may lead to arbitrary code execution

Description: A buffer overflow was addressed with improved bounds checking.

CVE-2021-30785: CFF of Topsec Alpha Team, Mickey Jin (@patch1t) of Trend Micro

**Kernel**

Available for: Apple TV 4K and Apple TV HD

Impact: A malicious attacker with arbitrary read and write capability may be able to bypass Pointer Authentication

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

CVE-2021-30769: Linus Henze (pinauten.de)

**Kernel**

Available for: Apple TV 4K and Apple TV HD

Impact: An attacker that has already achieved kernel code execution may be able to bypass kernel memory mitigations

Description: A logic issue was addressed with improved validation.

CVE-2021-30770: Linus Henze (pinauten.de)

**libxml2**

Available for: Apple TV 4K and Apple TV HD

Impact: A remote attacker may be able to cause arbitrary code execution

Description: This issue was addressed with improved checks.

CVE-2021-3518

**WebKit**

Available for: Apple TV 4K and Apple TV HD

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

Description: A type confusion issue was addressed with improved state handling.

CVE-2021-30758: Christoph Guttandin of Media Codings

**WebKit**

Available for: Apple TV 4K and Apple TV HD

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-2021-30795: Sergei Glazunov of Google Project Zero

**WebKit**

Available for: Apple TV 4K and Apple TV HD

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

Description: This issue was addressed with improved checks.

CVE-2021-30797:  Ivan Fratric of Google Project Zero

CVE-2021-31006: About the security content of tvOS 14.7

This issue was addressed with improved checks. This issue is fixed in iOS 14.8.1 and iPadOS 14.8.1, iOS 15.1 and iPadOS 15.1, macOS Monterey 12.0.1. A local attacker may be able to cause unexpected application termination or arbitrary code execution.

Released October 26, 2021

**Audio**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

Impact: A malicious application may be able to elevate privileges

Description: An integer overflow was addressed through improved input validation.

CVE-2021-30907: Zweig of Kunlun Lab

**ColorSync**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

Impact: Processing a maliciously crafted image may lead to arbitrary code execution

Description: A memory corruption issue in the processing of ICC profiles was addressed with improved input validation.

CVE-2021-30926: Jeremy Brown

Entry added May 25, 2022

**ColorSync**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

Impact: Processing a maliciously crafted image may lead to arbitrary code execution

Description: A memory corruption issue existed in the processing of ICC profiles. This issue was addressed with improved input validation.

CVE-2021-30917: Alexandru-Vlad Niculae and Mateusz Jurczyk of Google Project Zero

**Continuity Camera**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

Impact: A local attacker may be able to cause unexpected application termination or arbitrary code execution

Description: An uncontrolled format string issue was addressed with improved input validation.

CVE-2021-30903: Gongyu Ma of Hangzhou Dianzi University

Entry updated May 25, 2022

**CoreGraphics**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

Impact: Processing a maliciously crafted PDF may lead to arbitrary code execution

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

CVE-2021-30919

**GPU Drivers**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

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-2021-30900: Yinyi Wu (@3ndy1) of Ant Security Light-Year Lab

**IOMobileFrameBuffer**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

Impact: An application may be able to execute arbitrary code with kernel privileges. Apple is aware of a report that this issue may have been actively exploited.

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

CVE-2021-30883: an anonymous researcher

**Kernel**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

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-2021-30909: Zweig of Kunlun Lab

**Kernel**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

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

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

CVE-2021-30916: Zweig of Kunlun Lab

**Sidecar**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

Impact: A local attacker may be able to cause unexpected application termination or arbitrary code execution

Description: This issue was addressed with improved checks.

CVE-2021-30903: an anonymous researcher

**Status Bar**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

Impact: A user may be able to view restricted content from the Lock Screen

Description: A Lock Screen issue was addressed with improved state management.

CVE-2021-30918: videosdebarraquito

**Voice Control**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

Impact: A local attacker may be able to cause unexpected application termination or arbitrary code execution

Description: A use after free issue was addressed with improved memory management.

CVE-2021-30902: 08Tc3wBB of ZecOps Mobile EDR Team

**WebKit**

Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)

Impact: A malicious website using Content Security Policy reports may be able to leak information via redirect behavior 

Description: An information leakage issue was addressed.

CVE-2021-30888: Prakash (@1lastBr3ath)

CVE-2021-30903: About the security content of iOS 14.8.1 and iPadOS 14.8.1

This issue was addressed with improved checks. This issue is fixed in Security Update 2022-001 Catalina, macOS Big Sur 11.6.3. A malicious application may be able to bypass certain Privacy preferences.

Released January 26, 2022

**Audio**

Available for: macOS Big Sur

Impact: Parsing a maliciously crafted audio file may lead to disclosure of user information

Description: A buffer overflow issue was addressed with improved memory handling.

CVE-2021-30960: JunDong Xie of Ant Security Light-Year Lab

**iCloud**

Available for: macOS Big Sur

Impact: An application may be able to access a user's files

Description: An issue existed within the path validation logic for symlinks. This issue was addressed with improved path sanitization.

CVE-2022-22585: Zhipeng Huo (@R3dF09) of Tencent Security Xuanwu Lab (https://xlab.tencent.com)

**IOMobileFrameBuffer**

Available for: macOS Big Sur

Impact: A malicious application may be able to execute arbitrary code with kernel privileges. Apple is aware of a report that this issue may have been actively exploited.

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

CVE-2022-22587: an anonymous researcher, Meysam Firouzi (@R00tkitSMM) of MBition - Mercedes-Benz Innovation Lab, Siddharth Aeri (@b1n4r1b01)

**Kernel**

Available for: macOS Big Sur

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

Description: A buffer overflow issue was addressed with improved memory handling.

CVE-2022-22593: Peter Nguyễn Vũ Hoàng of STAR Labs

**Model I/O**

Available for: macOS Big Sur

Impact: Processing a maliciously crafted STL file may lead to unexpected application termination or arbitrary code execution

Description: An information disclosure issue was addressed with improved state management.

CVE-2022-22579: Mickey Jin (@patch1t) of Trend Micro

**PackageKit**

Available for: macOS Big Sur

Impact: An application may be able to access restricted files

Description: A permissions issue was addressed with improved validation.

CVE-2022-22583: Ron Hass (@ronhass7) of Perception Point, Mickey Jin (@patch1t)

Entry updated May 25, 2022

**TCC**

Available for: macOS Big Sur

Impact: A malicious application may be able to bypass certain Privacy preferences

Description: This issue was addressed with improved checks.

CVE-2021-30972: CVE-2021-30972: Xuxiang Yang (@another1024), Zhipeng Huo (@R3dF09) and Yuebin Sun (@yuebinsun2020) of Tencent Security Xuanwu Lab (xlab.tencent.com), Csaba Fitzl (@theevilbit) of Offensive Security, jhftss (@patch1t), Wojciech Reguła (@\_r3ggi)

Entry updated May 25, 2022

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