Apple iOS up to 12.5.3 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 has been found in Apple iOS up to 12.5.3 and classified as critical. The affected element is an unknown function of the component WebKit. This manipulation causes use after free. This vulnerability is handled as CVE-2021-30762. The attack can be initiated remotely. Additionally, an exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Apple iOS up to 12.5.3 (Smartphone Operating System). It has been declared as critical. Affected by this vulnerability is an unknown part of the component WebKit. 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. The summary by CVE is:

A use after free issue was addressed with improved memory management. This issue is fixed in iOS 12.5.4. 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 06/14/2021 as HT212548 as confirmed advisory (Website). It is possible to read the advisory at support.apple.com. This vulnerability is known as CVE-2021-30762. 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 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 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 12.5.4 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 (643), Tenable (241427) and EUVD (EUVD-2021-17679). Be aware that VulDB is the high quality source 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: 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: iOS 12.5.4

Timelineinfo

04/13/2021 🔍
06/14/2021 +62 days 🔍
06/14/2021 +0 days 🔍
06/20/2021 +6 days 🔍
07/29/2025 +1500 days 🔍

Sourcesinfo

Vendor: apple.com

Advisory: HT212548
Status: Confirmed

CVE: CVE-2021-30762 (🔍)
GCVE (CVE): GCVE-0-2021-30762
GCVE (VulDB): GCVE-100-177271
EUVD: 🔍
scip Labs: https://www.scip.ch/en/?labs.20150917

Entryinfo

Created: 06/20/2021 15:34
Updated: 07/29/2025 06:44
Changes: 06/20/2021 15:34 (16), 06/20/2021 15:35 (2), 06/20/2021 15:38 (28), 06/24/2021 08:25 (4), 04/21/2024 17:19 (26), 05/15/2024 17:15 (2), 06/26/2024 20:19 (2), 09/14/2024 12:24 (1), 01/30/2025 02:34 (29), 05/03/2025 17:53 (3), 07/10/2025 20:16 (2), 07/29/2025 06:44 (1)
Complete: 🔍
Cache ID: 216::103