Apple iOS/iPadOS up to 14.4.2 WebKit Storage use after free

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.
7.9$5k-$25k0.00

Summaryinfo

A vulnerability was found in Apple iOS and iPadOS up to 14.4.2 and classified as critical. This vulnerability affects unknown code of the component WebKit Storage. Executing a manipulation can lead to use after free. This vulnerability appears as CVE-2021-30661. The attack may be performed from remote. In addition, an exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Apple iOS and iPadOS up to 14.4.2 (Smartphone Operating System). It has been declared as critical. This vulnerability affects an unknown code of the component WebKit Storage. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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 presented 04/26/2021 by yangkang as HT212317 as confirmed advisory (Website). The advisory is shared for download at support.apple.com. This vulnerability was named CVE-2021-30661. Successful exploitation requires user interaction by the victim. Technical details are unknown but a private exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 07/29/2025). It is expected to see the exploit prices for this product increasing in the near future. 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. 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 14.5 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). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Vendor

Name

Version

License

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

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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: 🔍
Access: Private
Status: Attacked

EPSS Score: 🔍
EPSS Percentile: 🔍

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

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

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: iOS/iPadOS 14.5

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: HT212317
Researcher: yangkang
Status: Confirmed

CVE: CVE-2021-30661 (🔍)
GCVE (CVE): GCVE-0-2021-30661
GCVE (VulDB): GCVE-100-173968
EUVD: 🔍
scip Labs: https://www.scip.ch/en/?labs.20150917

Entryinfo

Created: 04/27/2021 08:25
Updated: 07/29/2025 05:53
Changes: 04/27/2021 08:25 (4), 04/27/2021 08:26 (15), 04/27/2021 08:29 (30), 04/30/2021 14:16 (1), 04/21/2024 14:47 (28), 05/15/2024 17:15 (2), 06/29/2024 02:33 (2), 09/14/2024 00:06 (1), 01/30/2025 02:34 (29), 03/05/2025 11:00 (2), 05/03/2025 22:04 (3), 07/29/2025 05:53 (1)
Complete: 🔍
Cache ID: 216::103

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

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you need the next level of professionalism?

Upgrade your account now!