Apple watchOS up to 7.3.3 WebKit Storage use after free

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

Summaryinfo

A vulnerability marked as critical has been reported in Apple watchOS up to 7.3.3. This issue affects some unknown processing of the component WebKit Storage. The manipulation leads to use after free. This vulnerability is documented as CVE-2021-30661. The attack can be initiated remotely. Additionally, an exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Apple watchOS up to 7.3.3 (Smartwatch Operating System) and classified as critical. This issue affects an unknown code of the component WebKit Storage. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

A use after free issue was addressed with improved memory management. This issue is fixed in Safari 14.1, iOS 12.5.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5, macOS Big Sur 11.3. 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..

The weakness was released 04/26/2021 by yangkang as HT212324 as confirmed advisory (Website). The advisory is shared at support.apple.com. The identification of this vulnerability is CVE-2021-30661. It demands that the victim is doing some kind of user interaction. Technical details are unknown but an 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 223935 (Linux Distros Unpatched Vulnerability : CVE-2021-30661), 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 7.4 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. The advisory contains the following remark:

A use after free issue was addressed with improved memory management.

The vulnerability is also documented in the databases at Zero-Day.cz (624), Tenable (223935) and EUVD (EUVD-2021-17578). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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Website

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: Use after free
CWE: CWE-416 / CWE-119
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: 223935
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2021-30661

Zero-Day.cz: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

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

Upgrade: watchOS 7.4

Timelineinfo

04/13/2021 🔍
04/26/2021 +13 days 🔍
04/26/2021 +0 days 🔍
04/27/2021 +1 days 🔍
07/29/2025 +1554 days 🔍

Sourcesinfo

Vendor: apple.com

Advisory: HT212324
Researcher: yangkang
Status: Confirmed

CVE: CVE-2021-30661 (🔍)
GCVE (CVE): GCVE-0-2021-30661
GCVE (VulDB): GCVE-100-174101
EUVD: 🔍
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 04/27/2021 11:28
Updated: 07/29/2025 06:02
Changes: 04/27/2021 11:28 (19), 04/27/2021 11:32 (27), 05/01/2021 13:53 (4), 04/21/2024 15:16 (26), 05/15/2024 17:15 (2), 06/29/2024 04:32 (2), 09/14/2024 00:06 (1), 01/30/2025 02:48 (29), 03/05/2025 11:00 (2), 05/03/2025 21:58 (3), 07/29/2025 06:02 (1)
Complete: 🔍
Cache ID: 216::103

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