Apple macOS up to 12.0 WebKit integer overflow

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7.5	$0-$5k	0.00

Summaryinfo

A vulnerability classified as critical was found in Apple macOS up to 12.0. Affected by this vulnerability is an unknown functionality of the component WebKit. Executing a manipulation can lead to integer overflow. This vulnerability is registered as CVE-2021-30952. It is possible to launch the attack remotely. Furthermore, an exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical was found in Apple macOS up to 12.0 (Operating System). This vulnerability affects an unknown function of the component WebKit. The manipulation with an unknown input leads to a integer overflow vulnerability. The CWE definition for the vulnerability is CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

An integer overflow was addressed with improved input validation. This issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing maliciously crafted web content may lead to arbitrary code execution.

The weakness was published 12/13/2021 by WeBin as HT212978 as confirmed advisory (Website). The advisory is available at support.apple.com. This vulnerability was named CVE-2021-30952. Successful exploitation requires user interaction by the victim. Technical details are unknown but an exploit is available. The advisory points out:

Processing maliciously crafted web content may lead to arbitrary code execution

It is declared as attacked. This issue was added on 03/05/2026 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 03/26/2026:

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Upgrading to version 12.1 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. The advisory contains the following remark:

An integer overflow was addressed with improved input validation.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-0631). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

Apple macOS

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: 7.6
VulDB Meta Temp Score: 7.5

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

NVD Base Score: 7.8
NVD Vector: 🔍

ADP CISA Base Score: 8.8
ADP CISA Vector: 🔍

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Integer overflow
CWE: CWE-190 / CWE-189
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Attacked

EPSS Score: 🔍
EPSS Percentile: 🔍

KEV Added: 🔍
KEV Due: 🔍
KEV Remediation: 🔍
KEV Ransomware: 🔍
KEV Notice: 🔍

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 12.1

Timelineinfo

04/13/2021 🔍
12/13/2021 +244 days 🔍
12/13/2021 +0 days 🔍
12/17/2021 +4 days 🔍
03/07/2026 +1541 days 🔍

Sourcesinfo

Vendor: apple.com

Advisory: HT212978
Researcher: WeBin
Status: Confirmed

CVE: CVE-2021-30952 (🔍)
GCVE (CVE): GCVE-0-2021-30952
GCVE (VulDB): GCVE-100-188650
CERT Bund: WID-SEC-2026-0631 - Apple macOS: Mehrere Schwachstellen

scip Labs: https://www.scip.ch/en/?labs.20180712

Entryinfo

Created: 12/17/2021 21:24
Updated: 03/07/2026 14:22
Changes: 12/17/2021 21:24 (10), 12/17/2021 21:25 (9), 12/17/2021 21:28 (28), 12/24/2021 07:16 (1), 03/05/2026 21:25 (43), 03/05/2026 23:01 (13), 03/07/2026 14:22 (7)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.