Apple macOS up to 12.0 WebKit cross-domain policy

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.
6.0	$0-$5k	0.00

Summaryinfo

A vulnerability has been found in Apple macOS up to 12.0 and classified as critical. This affects an unknown function of the component WebKit. This manipulation causes cross-domain policy. This vulnerability is registered as CVE-2021-30887. Remote exploitation of the attack is possible. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in Apple macOS up to 12.0 (Operating System). Affected by this vulnerability is an unknown part of the component WebKit. The manipulation with an unknown input leads to a cross-domain policy vulnerability. The CWE definition for the vulnerability is CWE-942. The product uses a cross-domain policy file that includes domains that should not be trusted. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was published 10/25/2021 by Narendra Bhati as HT212869 as confirmed advisory (Website). The advisory is shared at support.apple.com. This vulnerability is known as CVE-2021-30887. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The advisory points out:

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

The vulnerability scanner Nessus provides a plugin with the ID 236537 (Alibaba Cloud Linux 3 : 0162: webkit2gtk3 (ALINUX3-SA-2022:0162)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 12.0.1 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. The advisory contains the following remark:

A logic issue was addressed with improved restrictions.

The vulnerability is also documented in the vulnerability database at Tenable (236537). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Operating System

Vendor

Apple

Name

macOS

Version

12.0

License

commercial

Website

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

CPE 2.3info

🔍

CPE 2.2info

🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross-domain policy
CWE: CWE-942 / CWE-346 / CWE-345
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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

Nessus ID: 236537
Nessus Name: Alibaba Cloud Linux 3 : 0162: webkit2gtk3 (ALINUX3-SA-2022:0162)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Upgrade: macOS 12.0.1

Timelineinfo

04/13/2021 🔍
10/25/2021 +195 days 🔍
10/25/2021 +0 days 🔍
10/27/2021 +2 days 🔍
05/22/2025 +1303 days 🔍

Sourcesinfo

Vendor: apple.com

Advisory: HT212869
Researcher: Narendra Bhati
Status: Confirmed

CVE: CVE-2021-30887 (🔍)
GCVE (CVE): GCVE-0-2021-30887
GCVE (VulDB): GCVE-100-185545
scip Labs: https://www.scip.ch/en/?labs.20180712

Entryinfo

Created: 10/27/2021 09:07
Updated: 05/22/2025 08:47
Changes: 10/27/2021 09:07 (18), 10/27/2021 09:11 (29), 10/31/2021 15:12 (2), 05/22/2025 08:47 (16)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.