Apple Safari up to 14.1.0 WebKit integer overflow

CVSS Meta Temp Score
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CTI Interest Score
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7.9$0-$5k0.00

Summaryinfo

A vulnerability was found in Apple Safari up to 14.1.0. It has been rated as critical. This affects an unknown function of the component WebKit. This manipulation causes integer overflow. This vulnerability is tracked as CVE-2021-30663. The attack is possible to be carried out remotely. Moreover, an exploit is present. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Apple Safari up to 14.1.0 (Web Browser). It has been declared as critical. Affected by this vulnerability is 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. The summary by CVE is:

An integer overflow was addressed with improved input validation. This issue is fixed in iOS 14.5.1 and iPadOS 14.5.1, tvOS 14.6, iOS 12.5.3, Safari 14.1.1, macOS Big Sur 11.3.1. Processing maliciously crafted web content may lead to arbitrary code execution.

The weakness was disclosed 05/24/2021 as HT212534 as confirmed advisory (Website). The advisory is shared at support.apple.com. This vulnerability is known as CVE-2021-30663. It demands that the victim is doing some kind of user interaction. Technical details are unknown but an exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/29/2025). The advisory points out:

Processing maliciously crafted web content may lead to arbitrary code execution

It is declared as attacked. 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. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 11/03/2021 with a due date of 11/17/2021:

Apply updates per vendor instructions.

Upgrading to version 14.1.1 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 databases at Zero-Day.cz (626), Tenable (241427) and EUVD (EUVD-2021-17580). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.9

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

NVD Base Score: 8.8
NVD Vector: 🔍

CNA Base Score: 8.8
CNA Vector: 🔍

CVSSv2info

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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: No
Local: No
Remote: Yes

Availability: 🔍
Status: Attacked

EPSS Score: 🔍
EPSS Percentile: 🔍

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

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 241427
Nessus Name: RHEL 7 : webkitgtk4 (RHSA-2025:10364)

Zero-Day.cz: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Upgrade: Safari 14.1.1

Timelineinfo

04/13/2021 🔍
05/24/2021 +41 days 🔍
05/24/2021 +0 days 🔍
05/25/2021 +1 days 🔍
07/29/2025 +1526 days 🔍

Sourcesinfo

Vendor: apple.com

Advisory: HT212534
Status: Confirmed

CVE: CVE-2021-30663 (🔍)
GCVE (CVE): GCVE-0-2021-30663
GCVE (VulDB): GCVE-100-175777
EUVD: 🔍
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 05/25/2021 14:40
Updated: 07/29/2025 05:20
Changes: 05/25/2021 14:40 (10), 05/25/2021 14:41 (8), 05/25/2021 14:44 (27), 05/28/2021 18:30 (4), 04/21/2024 15:49 (26), 05/15/2024 17:15 (2), 06/28/2024 18:23 (2), 09/14/2024 12:24 (1), 02/03/2025 19:57 (29), 05/03/2025 18:53 (3), 07/10/2025 18:55 (2), 07/29/2025 05:20 (1)
Complete: 🔍
Cache ID: 216::103

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

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