CVE-2021-30855

Apple Security Advisory 2021-10-26-9

Severity Score

5.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

A validation issue existed in the handling of symlinks. This issue was addressed with improved validation of symlinks. This issue is fixed in Security Update 2021-005 Catalina, iOS 14.8 and iPadOS 14.8, iOS 15 and iPadOS 15, watchOS 8, macOS Big Sur 11.6. An application may be able to access restricted files.

Se presentó un problema de comprobación en el manejo de los enlaces simbólicos. Este problema se abordó con una comprobación de enlaces simbólicos mejorada. Este problema se corrigió en Security Update 2021-005 Catalina, iOS versión 14.8 y iPadOS versión 14.8, iOS versión 15 y iPadOS versión 15, watchOS versión 8, macOS Big Sur versión 11.6. Una aplicación podría acceder a archivos restringidos

macOS Big Sur 11.6 addresses buffer overflow, bypass, code execution, denial of service, integer overflow, out of bounds read, and use-after-free vulnerabilities.

*Credits: N/A

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Partial

Integrity

None

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-04-13 CVE Reserved
2021-08-24 CVE Published
2024-08-03 CVE Updated
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-59: Improper Link Resolution Before File Access ('Link Following')

CAPEC

References (6)

URL	Tag	Source
https://support.apple.com/en-us/HT212804	X_refsource_misc
https://support.apple.com/en-us/HT212805	X_refsource_misc
https://support.apple.com/en-us/HT212807	X_refsource_misc
https://support.apple.com/en-us/HT212814	X_refsource_misc
https://support.apple.com/en-us/HT212819	X_refsource_misc
https://support.apple.com/kb/HT212815	X_refsource_confirm

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC

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"				< 14.8 Search vendor "Apple" for product "Ipados" and version " < 14.8"		-		Affected
Apple Search vendor "Apple"		Iphone Os Search vendor "Apple" for product "Iphone Os"				< 14.8 Search vendor "Apple" for product "Iphone Os" and version " < 14.8"		-		Affected
Apple Search vendor "Apple"		Mac Os X Search vendor "Apple" for product "Mac Os X"				< 10.15.7 Search vendor "Apple" for product "Mac Os X" and version " < 10.15.7"		-		Affected
Apple Search vendor "Apple"		Mac Os X Search vendor "Apple" for product "Mac Os X"				10.15.7 Search vendor "Apple" for product "Mac Os X" and version "10.15.7"		-		Affected
Apple Search vendor "Apple"		Mac Os X Search vendor "Apple" for product "Mac Os X"				10.15.7 Search vendor "Apple" for product "Mac Os X" and version "10.15.7"		security_update_2020-001		Affected
Apple Search vendor "Apple"		Mac Os X Search vendor "Apple" for product "Mac Os X"				10.15.7 Search vendor "Apple" for product "Mac Os X" and version "10.15.7"		security_update_2021-001		Affected
Apple Search vendor "Apple"		Mac Os X Search vendor "Apple" for product "Mac Os X"				10.15.7 Search vendor "Apple" for product "Mac Os X" and version "10.15.7"		security_update_2021-002		Affected
Apple Search vendor "Apple"		Mac Os X Search vendor "Apple" for product "Mac Os X"				10.15.7 Search vendor "Apple" for product "Mac Os X" and version "10.15.7"		security_update_2021-003		Affected
Apple Search vendor "Apple"		Mac Os X Search vendor "Apple" for product "Mac Os X"				10.15.7 Search vendor "Apple" for product "Mac Os X" and version "10.15.7"		security_update_2021-004		Affected
Apple Search vendor "Apple"		Mac Os X Search vendor "Apple" for product "Mac Os X"				10.15.7 Search vendor "Apple" for product "Mac Os X" and version "10.15.7"		supplemental_update		Affected
Apple Search vendor "Apple"		Macos Search vendor "Apple" for product "Macos"				< 11.6 Search vendor "Apple" for product "Macos" and version " < 11.6"		-		Affected
Apple Search vendor "Apple"		Tvos Search vendor "Apple" for product "Tvos"				< 15.0 Search vendor "Apple" for product "Tvos" and version " < 15.0"		-		Affected
Apple Search vendor "Apple"		Watchos Search vendor "Apple" for product "Watchos"				< 8.0 Search vendor "Apple" for product "Watchos" and version " < 8.0"		-		Affected