Apple macOS up to 11.5.2 Preferences symlink

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.1	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Apple macOS up to 11.5.2 and classified as problematic. Affected by this issue is some unknown functionality of the component Preferences. The manipulation results in symlink. This vulnerability is identified as CVE-2021-30855. The attack is only possible with local access. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Apple macOS up to 11.5.2 (Operating System). Affected is an unknown code of the component Preferences. The manipulation with an unknown input leads to a symlink vulnerability. CWE is classifying the issue as CWE-61. The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files. This is going to have an impact on confidentiality, integrity, and availability.

The weakness was released 09/13/2021 by Zhipeng Huo as HT212804 as confirmed advisory (Website). The advisory is shared for download at support.apple.com. This vulnerability is traded as CVE-2021-30855. There are neither technical details nor an exploit publicly available. The advisory points out:

An application may be able to access restricted files

Upgrading to version 11.6 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. The advisory contains the following remark:

A validation issue existed in the handling of symlinks. This issue was addressed with improved validation of symlinks.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Operating System

Vendor

Apple

Name

macOS

Version

License

commercial

Website

Vendor: https://www.apple.com/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Symlink
CWE: CWE-61 / CWE-59
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: macOS 11.6

Timelineinfo

04/13/2021 🔍
09/13/2021 +153 days 🔍
09/13/2021 +0 days 🔍
09/21/2021 +8 days 🔍
09/30/2021 +9 days 🔍

Sourcesinfo

Vendor: apple.com

Advisory: HT212804
Researcher: Zhipeng Huo
Status: Confirmed

CVE: CVE-2021-30855 (🔍)
GCVE (CVE): GCVE-0-2021-30855
GCVE (VulDB): GCVE-100-183096
scip Labs: https://www.scip.ch/en/?labs.20180712

Entryinfo

Created: 09/21/2021 11:25
Updated: 09/30/2021 14:21
Changes: 09/21/2021 11:25 (19), 09/21/2021 11:28 (28), 09/30/2021 14:21 (1)
Complete: 🔍
Cache ID: 216::103