Apple tvOS up to 14.5 WebKit integer overflow

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7.9	$0-$5k	0.00

Summaryinfo

A vulnerability labeled as critical has been found in Apple tvOS up to 14.5. This issue affects some unknown processing of the component WebKit. Executing a manipulation can lead to integer overflow. This vulnerability is handled as CVE-2021-30663. The attack can be executed remotely. Additionally, an exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Apple tvOS up to 14.5 (Digital Media Player). It has been declared as critical. This vulnerability affects an unknown part 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 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 released 05/24/2021 as HT212532 as confirmed advisory (Website). The advisory is shared for download at support.apple.com. This vulnerability was named CVE-2021-30663. Successful exploitation requires user interaction by the victim. Technical details are unknown but a private exploit is available. The advisory points out:

Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited.

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. This issue was added on 11/03/2021 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 11/17/2021:

Apply updates per vendor instructions.

Upgrading to version 14.6 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). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Digital Media Player

Vendor

Apple

Name

tvOS

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: 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

AV	AC	Au	C	I	A
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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: No
Local: No
Remote: Yes

Availability: 🔍
Access: Private
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

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: tvOS 14.6

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: HT212532
Status: Confirmed

CVE: CVE-2021-30663 (🔍)
GCVE (CVE): GCVE-0-2021-30663
GCVE (VulDB): GCVE-100-175696
EUVD: 🔍
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 05/25/2021 12:33
Updated: 07/29/2025 05:20
Changes: 05/25/2021 12:33 (18), 05/25/2021 12:37 (29), 05/28/2021 09:54 (1), 04/21/2024 15:47 (23), 05/15/2024 17:15 (2), 06/28/2024 16:58 (2), 09/14/2024 12:24 (1), 02/03/2025 19:57 (29), 05/03/2025 19:02 (3), 07/10/2025 18:55 (2), 07/29/2025 05:20 (1)
Complete: 🔍
Cache ID: 216::103

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