CVE-2021-30771

Apple macOS libFontParser TTF Font Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability

Severity Score

7.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

An out-of-bounds write was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.4, iOS 14.6 and iPadOS 14.6, watchOS 7.5, tvOS 14.6. Processing a maliciously crafted font file may lead to arbitrary code execution.

Se abordó una escritura fuera de límites con una comprobación de entrada mejorada. Este problema es corregido en macOS Big Sur versión 11.4, iOS versión 14.6 y iPadOS versión 14.6, watchOS versión 7.5, tvOS versión 14.6. El procesamiento de un archivo de fuentes maliciosamente diseñado puede conllevar a una ejecución de código arbitrario

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Apple macOS. Interaction with the libFontParser library is required to exploit this vulnerability but attack vectors may vary depending on the implementation.
The specific flaw exists within the parsing of TTF fonts. Crafted data in a TTF font can trigger a write past the end of an allocated data structure. An attacker can leverage this vulnerability to execute code in the context of the current process.

*Credits: Mickey Jin (@patch1t) of Trend Micro

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Partial

Integrity

Partial

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-04-13 CVE Reserved
2022-02-16 CVE Published
2023-10-24 EPSS Updated
2024-08-03 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-787: Out-of-bounds Write

CAPEC

References (4)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://support.apple.com/en-us/HT212528	2022-03-25
https://support.apple.com/en-us/HT212529	2022-03-25
https://support.apple.com/en-us/HT212532	2022-03-25
https://support.apple.com/en-us/HT212533	2022-03-25

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Apple Search vendor "Apple"		Ipados Search vendor "Apple" for product "Ipados"				< 14.6 Search vendor "Apple" for product "Ipados" and version " < 14.6"		-		Affected
Apple Search vendor "Apple"		Iphone Os Search vendor "Apple" for product "Iphone Os"				< 14.6 Search vendor "Apple" for product "Iphone Os" and version " < 14.6"		-		Affected
Apple Search vendor "Apple"		Macos Search vendor "Apple" for product "Macos"				>= 11.0 < 11.4 Search vendor "Apple" for product "Macos" and version " >= 11.0 < 11.4"		-		Affected
Apple Search vendor "Apple"		Tvos Search vendor "Apple" for product "Tvos"				< 14.6 Search vendor "Apple" for product "Tvos" and version " < 14.6"		-		Affected
Apple Search vendor "Apple"		Watchos Search vendor "Apple" for product "Watchos"				< 7.5 Search vendor "Apple" for product "Watchos" and version " < 7.5"		-		Affected