Apple macOS WebKit type confusion

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 classified as critical was found in Apple macOS. The affected element is an unknown function of the component WebKit. The manipulation results in type confusion. This vulnerability is reported as CVE-2021-30758. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Apple macOS (Operating System) (version unknown). It has been classified as critical. Affected is an unknown function of the component WebKit. The manipulation with an unknown input leads to a type confusion vulnerability. CWE is classifying the issue as CWE-843. The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type. This is going to have an impact on confidentiality, integrity, and availability.

The weakness was disclosed 07/21/2021 by Christoph Guttandin as HT212602 as confirmed advisory (Website). The advisory is shared for download at support.apple.com. This vulnerability is traded as CVE-2021-30758. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The advisory points out:

Processing maliciously crafted web content may lead to arbitrary code execution

The vulnerability scanner Nessus provides a plugin with the ID 241427 (RHEL 7 : webkitgtk4 (RHSA-2025:10364)), which helps to determine the existence of the flaw in a target environment.

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

A type confusion issue was addressed with improved state handling.

The vulnerability is also documented in the vulnerability database at Tenable (241427). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Operating System

Vendor

Apple

Name

macOS

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: Type confusion
CWE: CWE-843
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: 241427
Nessus Name: RHEL 7 : webkitgtk4 (RHSA-2025:10364)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Timelineinfo

04/13/2021 🔍
07/21/2021 +99 days 🔍
07/21/2021 +0 days 🔍
07/23/2021 +2 days 🔍
07/10/2025 +1448 days 🔍

Sourcesinfo

Vendor: apple.com

Advisory: HT212602
Researcher: Christoph Guttandin
Status: Confirmed

CVE: CVE-2021-30758 (🔍)
GCVE (CVE): GCVE-0-2021-30758
GCVE (VulDB): GCVE-100-179592
scip Labs: https://www.scip.ch/en/?labs.20180712

Entryinfo

Created: 07/23/2021 10:29
Updated: 07/10/2025 20:16
Changes: 07/23/2021 10:29 (9), 07/23/2021 10:30 (8), 07/23/2021 10:33 (28), 07/28/2021 12:13 (1), 07/10/2025 20:16 (16)
Complete: 🔍
Cache ID: 216::103

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