Apple iOS/iPadOS up to 14.7.1 WebKit 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-$25k	0.00

Summaryinfo

A vulnerability classified as critical has been found in Apple iOS and iPadOS up to 14.7.1. This affects an unknown function of the component WebKit. The manipulation leads to use after free. This vulnerability is documented as CVE-2021-30858. The attack can be initiated remotely. Additionally, an exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Apple iOS and iPadOS up to 14.7.1 (Smartphone Operating System). This issue affects some unknown processing of the component WebKit. 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 weakness was released 09/13/2021 as HT212807 as confirmed advisory (Website). It is possible to read the advisory at support.apple.com. The identification of this vulnerability is CVE-2021-30858. It demands that the victim is doing some kind of user interaction. Technical details are unknown but an exploit is available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 05/18/2025). 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 236674 (Alibaba Cloud Linux 3 : 0079: webkit2gtk3 (ALINUX3-SA-2021:0079)), 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 14.8 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 (662) and Tenable (236674). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Smartphone Operating System

Vendor

Apple

Name

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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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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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: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 236674
Nessus Name: Alibaba Cloud Linux 3 : 0079: webkit2gtk3 (ALINUX3-SA-2021:0079)

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 14.8

Timelineinfo

04/13/2021 🔍
09/13/2021 +153 days 🔍
09/13/2021 +0 days 🔍
09/14/2021 +1 days 🔍
05/18/2025 +1342 days 🔍

Sourcesinfo

Vendor: apple.com

Advisory: HT212807
Status: Confirmed

CVE: CVE-2021-30858 (🔍)
GCVE (CVE): GCVE-0-2021-30858
GCVE (VulDB): GCVE-100-182531
scip Labs: https://www.scip.ch/en/?labs.20150917

Entryinfo

Created: 09/14/2021 08:32
Updated: 05/18/2025 16:20
Changes: 09/14/2021 08:32 (18), 09/14/2021 08:35 (28), 09/16/2021 14:10 (2), 04/21/2024 17:53 (26), 05/15/2024 17:15 (1), 06/25/2024 03:06 (2), 07/29/2024 22:36 (19), 09/15/2024 00:30 (1), 01/30/2025 00:15 (11), 05/03/2025 12:01 (3), 05/18/2025 16:20 (2)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.